汽车专业英语读译教程（第3版）TEXT C课后练习题（EXERCISES）参考答案UNIT 1 AUTOMOTIVE BASICSUNIT 2 ENGINE MECHANICALTEXT C Piston and Rod Repair. Choose the best answer for each of the followings:1. Most pistons have an arrow or notch on the top of the piston, indicating that this side should face _a_.a. the front of the engineb. the rear of the enginec. the left side of the engined. the right side of the engine2. When hone marks intersect at _c_ the cross-hatch angle is most satisfactory for proper seating of the rings.a. 30-40b. 40-50c. 50-60d. 60-703. Using a_d_, check the piston ring gap with the ring positioned at least 0.50 inch. (12 mm) from the bottom of the cylinder bore.a. micrometerb. bore gagec. telescope gauged. feeler gauge4. The engine crankshaft and connecting rod bearing clearances can be determined by the use of _b_.a. bore gageb. Plastigagec. telescope gauged. feeler gauge.Translate the following paragraphs into Chinese.There are several engine types which are identified by the number of cylinders and the way the cylinders are laid out. Motor vehicles will have from 3 to 12 cylinders which are arranged in the engine block in several configurations. In-line engines have their cylinders arranged in a row. 3, 4, 5 and 6 cylinder engines commonly use this arrangement. The V arrangement uses two banks of cylinders side-by-side and is commonly used in V-6, V-8, V-10 and V-12configurations. Flat engines use two opposing banks of cylinders and are less common than the other two designs. They are used in Subarus and Porsches in 4 and 6 cylinder arrangements as well as in the old VW beetles with 4 cylinders. Flat engines are also used in some Ferraris with 12 cylinders. 可以通过气缸的数量和气缸的布局方式来确定发动机有几种类型。机动辆将有3到12个气缸，这些气缸以若干种不同的配置布置在发动机气缸体中。直列式发动机的气缸排列成一列。3缸、4缸、5缸和6缸发动机通常使用这种布置。V型发动机将气缸布置成并排的两列，并且通常采用V-6、V-8、V-10和V-12型布置。水平对置式发动机使用相对的两列气缸，并且不如其他两种设计常见。它们以4缸和6缸布置的形式用于斯巴鲁和保时捷汽车，以及用在老式的4缸大众甲壳虫汽车上。水平对置式发动机还被用于一些12缸法拉利汽车上。UNIT 3 FUEL INJECTION SYSTEMS（1）TEXT C Troubleshooting the EFI System. Answer the following questions：1. What does the term false air mean? How do you check it?Another likely cause of trouble in pulsed systems is air leaks between the air-flow sensor and the intake valves. These leaks are often called false air because it is air that has not been measured by the air-flow sensor. As a result, the control unit may not provide fuel to burn with the excess air, leading to a lean condition and driveability or emission problems. If you suspect an air intake leak, there are many possible sources. The soft rubber ductwork can crack and split with age and under-hood heat. Check clamps for tightness. Dont forget the vacuum hoses to the brake booster, the fuel pressure regulator, the evaporative fuel control system, and other places, such as vacuum diaphragms in the heater system inside the car. Check the intake manifold connection to the cylinder head, fuel injector seals, the auxiliary air valve, and the EGR valve, if fitted. Check openings to the crankcase, such as the dipstick, PCV valve, and oil-filler cap for air-tight fits. Check anything downstream of the air-flow sensor that could leak air into the system.Check for leaks by pressurizing the intake system with air and then spraying a leak detector on the suspected area. An air hose inserted into the fitting for the auxiliary air valve or the idle speed stabilizer can be used to apply low pressure; only about 0.3 bar (5 psi) is needed. A spray bottle of soapy water can serve as a leak detector. Block the throttle so that its open. Any bubbles will indicate a leak. Also listen for the sound of escaping air. You may have to plug the air-flow sensor intake and the exhaust tailpipe to hold enough pressure in the system.NOTEOn systems with an air-mass sensor, it is necessary to block the sensor inlet to hold any pressure in the system. A styrofoam coffee cup clamped in the air-mass sensor inlet makes a handy temporary plug. An alternate leak-detection method involves squirting solvent around suspected leak locations with the engine idling. An rpm increase indicates a leak. Be sure to use an approved solvent with a high-temperature flashpoint. You can also use propane, which tends to be drawn in better than solvent.Remember though, if the engine has an idle-speed stabilizer, it will ask any rpm increase. If you can sample CO in the exhaust ahead of the catalytic converter, look for CO increase some seconds after applying the solvent as an indication of an air leak.2. How do you correct a leak?To correct a leak, start by tightening clamps; you might have to replace the hose or ducting, or replace a gasket. Remember, its the small intake air leaks that cause trouble, where the engine runs, but poorly. If theres a big air leak, the engine probably wont run at all.Translate the following paragraphs into Chinese：