组合车辆测试 – 美国驾照

组合车辆测试

题库共有99题，每次随机刷新20题，正确率80%以上即为通过。

正确！解释：防止侧翻的两点——货物尽量低、弯道慢行。 / Right! EXPLANATION: The following two things will help you prevent rollover–keep the cargo as close to the ground as possible and drive slowly around turns.

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防止侧翻有两件事：(1) 让货物尽量贴近地面；(2) / There are two things that a driver can do to prevent a roll over. They are: (1) keep the cargo as close to the ground as possible; and (2):

把五轮自由间隙调到尽可能小 / Keep the fifth wheel's free play as tight as possible

确保制动调整正确 / Make sure that the brakes are properly adjusted

转弯时慢行 / Go slowly around turns

正确！解释：挂车应略低于五轮，使牵引车倒入时能将其**轻微托起**。挂车太低可能顶伤鼻部，太高可能无法正确挂接。 / Bingo! EXPLANATION: The trailer should be low enough that it is raised slightly by the tractor when the tractor is backed under it. If the trailer is too low, the tractor may strike and damage the trailer nose; if the trailer is too high, it may not couple correctly.

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当你把牵引车倒到挂车下方时，应当预期： / When backing your tractor under a trailer, you should expect:

牵引车倒入车底时，挂车会被轻微托起 / Trailer will be lifted slightly when the tractor backs under it

牵引销端面与五轮顶面齐平 / End of the kingpin is even with the top of the fifth wheel

挂车支腿完全放下 / Trailer landing gear to be fully extended

正确！解释：确保气管和电缆**不缠绕、不被夹、不拖地**，并留有**足够转弯余量**。 / Right! EXPLANATION: Make sure air and electrical lines are not tangled, pinched, dragging against tractor parts, and have enough slack for turns.

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连接牵引车与挂车的气管和电缆应当： / Air and electrical lines from the tractor to the trailer should be

固定好但要留足转弯余量。 / secured but with enough slack for turns.

搁在牵引车车架上。 / resting on the frame of the tractor.

拉得很紧几乎没余量。 / pulled tight with very little slack.

正确！解释：应急气路发生重大泄漏会使牵引车保护阀关闭，并触发挂车紧急制动。但只有当挂车气罐仍有压力时，制动才能保持。 / Right! EXPLANATION: A major leak in the emergency line will cause the tractor protection valve to close and the trailer emergency brakes to come on. But the brakes will hold only if there is air pressure in the trailer air tank.

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行驶中若应急气路破裂或被扯断，压力损失会导致： / Your emergency air line breaks or gets pulled apart while you are driving. The loss of pressure will cause the:

挂车紧急制动会介入 / Emergency trailer brakes to come on

挂车供气阀会打开 / Trailer supply valve will open

在气压降到 10 PSI 之前不会发生任何事 / Nothing will happen until air pressure reaches 10 PSI

空气压缩机会卸载而不再充气 / Air compressor to unload instead of pumping air

完全正确！解释：车辆的**重心高度**对操控很重要；重心越高，越容易翻车。 / Exactly! EXPLANATION: The height of the vehicle’s center of gravity is very important for safe handling. A high center of gravity means you are more likely to tip over.

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通常而言，卡车的重心越高， / In general, the higher your truck’s center of gravity, the

越容易快速过弯。 / easier it is to turn around corners.

转弯时越稳定。 / more stable it is when turning.

越容易侧翻。 / easier it is to turn over.

完全正确！解释：检查期间要先**固定车辆**：变速箱挂**空挡**，拉驻车制动，熄火并带走钥匙，防止他人移动。 / Exactly! EXPLANATION: Before inspection the trailer while coupling you need to secure the vehicle. Put transmission in neutral. Put parking brakes on. Shut off engine and take key with you so someone else won’t move truck while you are under it.

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解挂并检查挂车支腿时，牵引车变速箱应挂在什么挡位？ / What gear should the tractor engine be in after you uncouple the trailer and are inspecting the trailer supports?

空挡（Neutral） / Neutral

高速倒挡（High reverse） / High reverse

低速倒挡（Low reverse） / Low reverse

完全正确！解释：若右转无法不占用他车道，应在**完成**转弯时外摆，并让车辆后部贴近路缘，防止他车从右侧超车。 / Exactly! EXPLANATION: If you are driving a truck or bus that cannot make the right turn without swinging into another lane, turn wide as you complete the turn. Keep the rear of your vehicle close to the curb. This will stop other drivers from passing you on the right.

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在不进入其他车道的前提下，最安全的转弯方式是： / What is the safest way for you to make a turn without entering another traffic lane?

若必须压到对向车道且看见来车，就停下并倒车让行。 / If you must cross into the oncoming lane to make a turn and you see vehicles coming toward you, stop and back up for them.

应在**开始**转弯前外摆。 / You should turn wide before you start the turn.

应在**完成**转弯时外摆。 / You should turn wide as you complete the turn.

正确！解释：三挂的**后向放大**约为 3.5，也就是说，它最后一节挂车**比五轴牵引车**更容易翻车约 3.5 倍；双挂约 2。 / Right! EXPLANATION: Triples have a rearward amplification of 3.5. This means you can roll the last trailer of triples 3.5 times as easily as a five-axle tractor. While the rearward amplification of a double is around 2.

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哪种牵引车-挂车组合最容易发生“鞭甩效应”（crack‑the‑whip）导致翻车？ / Which type of truck-trailer combination has the greatest chance of a “crack-the-whip” rollover?

单一牵引车‑半挂 / A single tractor trailer

牵引车拉两挂 / A tractor pulling two trailers

牵引车拉三挂 / A tractor pulling three trailers

open, move the vehicle forward slowly, and apply trailer brakes with the hand control or trolley valve. You should feel the brakes come on. This tells you the trailer brakes are connected and working. / 正确！解释：检查气压正常，释放驻车与行车制动，确认挂车供气按入/开启，车辆低速前移，用手控阀施加挂车制动，应能感觉到制动介入——这说明挂车制动已连接且工作正常。 / Correct! EXPLANATION: Check for normal air pressure, release the parking brakes, release the service brake, make sure the trailer air supply is in

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仅测试挂车行车制动时，各气阀的正确状态是？ / Which answer is correct for the air valves when testing the trailer service brakes only?

以上都不对 / No answers are correct

open; Trolley: applied / 行车制动：释放；驻车制动：释放；挂车供气：按入/开启；手控阀：施加 / Service Brake: off; Parking Brake: off; Trailer air supply: in

行车制动：释放；驻车制动：释放；挂车供气：拉出；手控阀：施加 / Service Brake: off; Parking Brake: off; Trailer air supply: out; Trolley: applied

open; Trolley: released / 行车制动：释放；驻车制动：释放；挂车供气：按入/开启；手控阀：释放 / Service Brake: off; Parking Brake: off; Trailer air supply: in

正确！解释：先略微升起挂车支腿离地；保持挂车制动锁定，挂低挡轻轻前拉以检查是否真正锁紧。 / Correct! EXPLANATION: Raise trailer landing gear slightly off ground. Pull tractor gently forward while the trailer brakes are still locked to check that the trailer is locked onto the tractor.

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如何测试牵引车与挂车的连接是否牢靠？ / How should you test the tractor trailer connection for security?

挂挡后猛冲向前用力拽 / Put the tractor in gear and pull ahead with a sharp jerk

在锁住挂车制动的情况下前后晃动车辆 / Rock the trailer back and forth with the trailer brakes locked

挂低挡轻轻向前顶住已锁定的挂车制动，然后检查挂接情况 / Pull gently forward in low gear against the locked trailer brakes, then inspect the coupling

正确！解释：把牵引车向前挪到五轮刚好脱离挂车，但**车架仍在挂车下方**。若支腿塌陷或下陷，可防止挂车落地。 / Correct! EXPLANATION: Pull tractor forward until fifth wheel comes out from under the trailer but stop with tractor frame under trailer preventing the trailer from falling to ground if landing gear should collapse or sink.

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解挂后检查挂车支腿时，牵引车应停在何处？ / Where should the tractor be when you inspect the landing gear after uncoupling the trailer?

让牵引车车架仍在挂车底下 / With the tractor frame under the trailer

让五轮正对牵引销正下方 / With the fifth wheel directly beneath the kingpin

让牵引车完全离开挂车 / Completely cleared from the trailer

完全正确！解释：检查时要确保不超载，货物**分布均匀且捆扎牢固**，并尽量降低重心。 / Exactly! EXPLANATION: As part of your Vehicle inspection, make sure the truck is not overloaded and the cargo is balanced and secured properly.

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为防止侧翻，货物应当 / To prevent rollover, cargo should be

在整台（或多台）挂车上**均匀分布**，并尽量**降低重心**。 / spread evenly across the trailer(s) and as low as possible.

尽量堆在靠近车门的位置。 / stacked closest to the doors.

尽量堆在车组前部。 / stacked as close to the front of the rig as possible.

答对了！解释：确保空气压力达到**正常值**。 / Bingo! EXPLANATION: Make sure air pressure is up to normal.

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在整套空气系统达到下列哪种状态之前，你不应把牵引车倒入挂车底下： / You should not back a tractor under a trailer until the whole air system is:

达到正常气压。 / At normal pressure

在 60–80 PSI 之间。 / Between 60 and 80 PSI

达到最大气压的一半。 / Half the maximum pressure

答对了！解释：货物越多，**重心**越高，车辆越容易侧翻。满载车在事故中侧翻的概率大约是空车的**10 倍**。 / Bingo! EXPLANATION: When more cargo is piled up in a truck, the “center of gravity” moves higher up from the road. The truck becomes easier to turn over. Fully loaded rigs are ten times more likely to roll over in a crash than empty rigs.

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卡车在满载时更容易侧翻，并且 / Trucks roll over more easily when fully loaded and are

发生事故时侧翻的几率是空车的十倍。 / ten times more likely to roll over in a crash than empty rigs.

发生事故时侧翻的几率是空车的两倍。 / two times more likely to roll over in a crash than empty rigs.

发生事故时侧翻的几率是空车的五倍。 / five times more likely to roll over in a crash than empty rigs.

正确！解释：检查锁紧杆是否处于锁定位置；若不能锁定，则挂接尚未完成。 / Right! EXPLANATION: Check that the locking lever is in the lock position. If the locking lever does not go into the locked position the coupling is not complete.

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若五轮锁紧杆在钳口已抱住牵引销后仍未锁定，这意味着： / The fifth wheel locking lever is not locked after the jaws close around the kingpin; this means:

你可以把五轮调到更有利的载荷分配位置 / You can set the fifth wheel for weight balance

驻车锁未启用，你可以直接开走 / The parking lock is off, and you may drive away

挂接不正确，必须修复后才能驾驶该车组 / The coupling is not right and should be fixed before driving the coupled unit

答对了！解释：熄火以便听得更清楚；反复施加并释放挂车制动，应能听到作动与泄气的声音。 / Bingo! EXPLANATION: Shut the engine off so you can hear the brakes. Apply and release trailer brakes and listen for sounds of trailer brakes being applied and released. You should hear the brakes move when applied and air escape when the brakes are released.

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向挂车供气后，要确认气管未交叉且挂车制动工作正常。正确做法是： / After you supply air to the trailer, make sure the airlines are not crossed and the trailer brakes are working. This is done by:

在驾驶室里打开驻车制动。 / Turning on the parking brakes from the cab.

施加并释放挂车制动，**听**刹车作动声音。 / Applying and releasing the trailer brakes and listening for brake sounds.

抬起制动踏板。 / Lifting the brake pedal.

答对了！解释：解锁五轮：把解锁手柄拉到“**OPEN**”位置。 / Bingo! EXPLANATION: To unlock the fifth-wheel pull the release handle to “open” position.

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要解锁五轮（fifth wheel），应将解锁手柄拉到 _______ 位置。 / To unlock the fifth wheel, pull the release handle to the _______ position.

空挡（neutral） / neutral

打开（open） / open

关闭（closed） / closed

答对了！解释：虽说车越重刹车做功越大，但重型车在**满载**时（轮胎、弹簧、减震）工作效果最好；空车抓地差，制动距离反而更长。 / Bingo! EXPLANATION: The heavier the vehicle, the more work the brakes must do to stop it, and the more heat they absorb. But the brakes, tires, springs, and shock absorbers on heavy vehicles are designed to work best when the vehicle is fully loaded. Empty trucks require greater stopping distances because an empty vehicle has less traction.

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牵引车配哪种状态的挂车时，制动距离最短？ / A tractor with a(n) _______ trailer requires the shortest amount of stopping distance.

轻载。 / lightly loaded

空载。 / empty

满载。 / fully loaded

完全正确！解释：行车气路的大泄漏在你踩刹车前未必明显；一旦踩下，压力会迅速降低，降到足够低时，挂车**紧急/弹簧制动**会介入。 / Exactly! EXPLANATION: You may not notice a major leak in the service line until you try to put the brakes on. Then, the air loss from the leak will lower the air tank pressure quickly. If it goes low enough, the trailer emergency brakes will come on.

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行车气路发生重大泄漏且你踩下刹车时，行车气压会泄掉并导致： / You have a major leak in the service line, and you put on the brakes. Service air pressure will escape and cause the:

挂车储气筒气压耗尽。 / Trailer tank pressure to be lost

牵引车弹簧制动抱死。 / Tractor spring brakes to lock on

spring brakes to come on / 挂车紧急/弹簧制动介入。 / Trailer emergency

正确！解释：铁路道口尤其麻烦，拖带**底盘离地间隙低**的挂车时更要当心，别冒险卡在道口中央。 / Bingo! EXPLANATION: Railroad tracks can also cause problems, particularly when pulling trailers with a low underneath clearance. Don’t take a chance on getting hung up halfway across.

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底盘离地间隙较低的车辆在铁路道口更危险，因为 / Low underneath clearance vehicles can be risky at railroad crossings because

更容易在不平路面发生折刀。 / they are more likely to jackknife on the uneven ground.

更容易被抬高的道口卡住。 / they are more likely to get stuck on raised railroad crossings.

可能需要更长的制动距离。 / they may take longer to stop.

正确！解释：一个常用规则：**40 mph 以下**时，每 **10 英尺**车长应留 **1 秒**间隔；更高速度需**再加 1 秒**。 / Right! EXPLANATION: One good rule says you need at least one second for each 10 feet of vehicle length at speeds below 40 mph. At greater speeds, you must add 1 second for safety.

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良好路况下，你与前车至少应保持的时间间隔为：每 ______ 英尺车长留出一秒。 / Under good driving conditions, you should leave at least one second of space between your vehicle and the vehicle ahead for every ___ feet of your vehicle’s length.

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完全正确！解释：先用低速档开始摇起支腿，脱重后换高速档并**完全收起**；切勿让其只升到一半——可能会**挂到道口**等障碍。收好后把摇柄固定在支架上。 / Exactly! EXPLANATION: Use low gear range to begin raising the landing gear, once free of weight, switch to the high gear range. Raise the landing gear all the way up. Never drive with landing gear only part way up as it may catch on railroad tracks or other things. After raising landing gear, secure the crank handle safely.

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已与半挂车完成挂接。起步前，挂车前支腿应置于何种位置？ / You have coupled with a semi-trailer. In what position should you put the front trailer supports before driving away?

支腿升到一半并取下摇柄 / Raised half way with the crank handle removed

支腿完全升起，并把摇柄固定在支架上 / Fully raised with the crank handle secured in its bracket

离顶端三圈并把摇柄固定在支架上 / Three turns off the top with the crank handle secured in its bracket

答对了！解释：挂车开始形成折刀（jackknife）的最早迹象，是你会从后视镜里看到它向外摆动。 / Bingo! EXPLANATION: The earliest way to notice that your trailer is jackknifing is to see it swinging out in your mirrors.

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判断挂车是否开始侧滑的最佳方法是 / The best way to tell if your trailer has started to skid is to

在驾驶室里感到被“拉扯”。 / feel for "pulling" in the cab.

听到车轮打滑的声音。 / hear the wheels skidding.

从后视镜里看见挂车甩出。 / see it in your mirrors.

正确！解释：大型组合车在空载或轻载时悬架更硬、制动更“猛”，抓地更差，车轮更容易抱死，因此反而更难刹住。 / Right! EXPLANATION: Large combination vehicles take longer to stop when they are empty than when they are fully loaded. When lightly loaded, the very stiff suspension springs and strong brakes give poor traction and make it very easy to lock up the wheels.

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组合车辆在空载时比满载时更难刹住，因为 / Combination vehicles take longer to stop when they are empty than when they are fully loaded, because

抓地力更小。 / there is less traction.

重心更低。 / the center of gravity is lower.

你不太可能那么用力刹车。 / you're unlikely to brake as hard.

答对了！解释：在把牵引车倒入挂车底下前，确保空气压力达到**正常值**。 / Bingo! EXPLANATION: Make sure air pressure is up to normal before backing under the trailer.

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在整套空气系统 ______ 之前，你不应把牵引车倒入挂车底下。 / You should not back a tractor under a trailer until the whole air system is

在 60–80 PSI 之间。 / between 60 and 80 psi.

达到正常气压。 / at normal pressure.

降到最大气压的一半。 / bled down to half the maximum pressure.

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