( ) is a sheet metal shell with windows, doors, a hood, and a trunk deck built into it. A:clutch B:body C:engine D:chass

A crankshaft’s job in an engine is to ( )
A:change linear motion into rotational motion
B:keep cylinder heads in place
C:convert fuel energy into mechanical energy
D:deliver fuel to the cylinders
答案: change linear motion into rotational motion

The crank connecting rod mechanism consists of three parts—( ).
A:engine block group
B:crankshaft and flywheel group
C:camshaft and valve group
D:piston and connecting rod group
答案: engine block group
,crankshaft and flywheel group
,piston and connecting rod group

Crank-connecting rod mechanism is the main working mechanism of reciprocating internal combustion engine.（ ）
A:对
B:错
答案: 对

The top of the cylinder block is covered with the cylinder head. （ ）
A:错
B:对
答案: 对

An average air/fuel ratio for good combustion is about ( ) by weight.
A:13:1
B:18:1
C:15:1
D:20:1
答案: 15:1

A valve consists of a( )and ( )stem. （ ）
A:tappet
B:rocker
C:stem
D:head
答案: stem
,head

The ( )provides the force necessary to close the valve and hold it tightly against its seat.
A:valve spring
B:tappet
C:valve
D:rod
答案: valve spring

The inlet valve is opened before TDC and closed after BDC.（ ）
A:对
B:错
答案: 对

Camshaft’s function is to deliver spark positively and timely in a definite sequence. （ ）
A:错
B:对
答案: 错

The ( ) that the injector is open, the more fuel is injected.
A:smaller
B:shorter
C:bigger
D:longer
答案: longer

Most vehicles today use ( ) injector per cylinder.
A:4
B:1
C:2
D:3
答案: 1

The （ ）on the fuel tank is used to keep the fuel from splashing out, release the vacuum created by the fuel removing, and prevent vapors from escaping directly into the atmosphere.
A:baffle
B:sump
C:fuel cap
D:filter
答案: fuel cap

For a diesel fuel goes to the carburetor, then to the fuel nozzles.（ ）
A:错
B:对
答案: 错

The fuel system supplies gasoline or diesel fuel to the oil pan. （ ）
A:对
B:错
答案: 错

What is the cooling agent in the liquid cooling system? ( )
A:air
B:coolant
C:lubrication
D:gasoline
答案: coolant

The water pump uses ( ) to send fluid to the outside while it spins, causing fluid to be drawn from the center continuously.
A:gas force
B:centrifugal force
C:gravity
D:friction
答案: centrifugal force

The cooling system of a water-cooled engine consists of the engine’s water jacket, a（ ）and radiator cap, a cooling fan (electric or belt-driven), hoses, and usually an expansion (overflow) tank.
A:water pump
B:radiator
C:thermostat
D:fuel cap
答案: water pump
,radiator
,thermostat

The cooling system is designed to work all the time when the engine is running.（ ）
A:错
B:对
答案: 错

Some engines are coated the inside of the top of the cylinder head with a thin layer of ceramic to reduce the amount of heat that is transferred from the combustion chamber to the metal parts of the engine. （ ）
A:错
B:对
答案: 对

1.For an engine to make the best use of the fuel, the spark should occur before the piston reaches the top of（ ）。
A:the compress stroke
B:the exhaust stroke
C:the intake stroke
D:the compression stroke
答案: the compression stroke

The piston speed increases as the engine speed increases. This means that the faster the engine goes, the spark has to occur（ ）。
A:uncertain
B:later
C:no change is necessary
D:earlier
答案: earlier

According to your understanding, retarding the timing may also eliminate（ ）。
A:ignition
B:knocking
C:compression
D:combustion
答案: knocking

The primary role of the distributor is to distribute high voltage from the（ ）to the correct cylinder.
A:coil
B:spark plug
C:rotor
D:piston
答案: coil

Functions of ignition system are （ ）
A:ignite the mixture piston
B:send spark to correct cylinder
C:create a spark
D:control the timing of spark
答案: ignite the mixture piston
,send spark to correct cylinder
,create a spark
,control the timing of spark