试题查看

首页 > 专升本考试 > 试题查看
【单选题】

The first automobile was invented more than two hundred years ago. It used steam for power and had wooden wheels. The first automobile may have been simple and primitive, but it was an extremely important invention. The automobile today is the primary means of land transportation. It has produced more changes in our daily life than any other machines.

Almost all gasoline engines work in the same way—with four movements, or strokes, of a piston in a cylinder. The first stroke pulls the fuel mixture (gasoline and air) into the cylinder. The second stroke compresses the fuel mixture.A、spark plug produces a spark that ignites the fuel mixture and causes the third stroke. The final stroke removes any waste gases which might remain in the cylinder.
The preceding paragraph explains what happens inside the cylinder to make the piston move. When the piston is pushed down by the explosion in the third stroke, it pushes the connecting roD、This rod rotates the crankshaft. The crankshaft is connected to other parts which turn the wheels. Most cars today have four, six, or eight cylinders.
The author suggests that the invention of the car was ______.
A、important
B、unimportant
C、somewhat important
D、very important
查看答案解析

参考答案:

正在加载...

答案解析

正在加载...

根据网考网移动考试中心的统计,该试题:

5%的考友选择了A选项

6%的考友选择了B选项

26%的考友选择了C选项

63%的考友选择了D选项

你可能感兴趣的试题

Theteachertoldusthatthesun______intheeasAskher______shecancametoseeusoff.A.thatBSheispleasedwith______youhavegivenherand______fromBeijingtoGuangzhou!A.HowlongwaIgetalotoflettersatthistimeofyearfrompeoTheearliestimmigrantstoNorthAmericafound