The question whether there is life on Ma

题型:阅读理解

问题:

The question whether there is life on Mars (火星) has made the public think a lot for more than a century. The closest look showed Mars to be a dusty, cold world, covered by air too thin to breathe. A British spaceship and Europe's Mars spaceship plan to land on Mars or enter orbit (轨道) around it. One of the NASA’s (美国宇航局) spaceships is expected to land on January 3, the other is going to land on the opposite side of Mars on January 24. Since 1960, over twenty spaceships sent to Mars have failed. Most have been lost on flying up or landing because those are the most difficult times of any flights.     Scientists wanted to find out whether there was water in Mars. In October, a team of scientists reported that Mars had been a dry wasteland. But weeks later, a second team reported differently that they had found some marks showed clearly that they were made by the rivers. Such marks told us that Mars was a warmer place billions of years ago — just as life first appeared here on Earth. Scientists at once raise a question: if what they said is true, what happened on Mars? Then what about the earth?

小题1:Which is right about Mars?

A.It’s cold without dust.

B.There is no water or air.

C.It’s warm with some thin air.

D.It’s a dusty, cold world almost without air.小题2:Two NASA’s spaceships _______________.

A.will land on the different sides of Mars

B.will land on the same day

C.will enter orbit around Mars

D.will land with a man小题3:The most difficult times of a flight are _______________.

A.taking off

B.flying up and arriving

C.entering the orbit and landing

D.leaving the earth and entering the orbit小题4:A team of scientists reported that there might be_____________ in Mars.

A.nothing but air

B.nothing

C.water billions of years ago

D.thick air and lakes小题5:What are scientists worried about when they raise the question?

A.Life disappeared on Mars.

B.Spaceships can’t land on Mars.

C.The air on the earth gets less and less.

D.The earth might be changed like Mars

考点:新闻报道类阅读
题型:阅读理解

统计表与统计图相比

A.统计表数据精确,统计图数据粗略,因此有统计表时不需要统计图

B.统计图可使人们对事物间的数量关系一目了然、印象清晰,因此不需要统计表

C.统计表与统计图各有优缺点,要根据实际需要正确使用

D.有统计图时必须附有统计表

E.统计表和统计图只能使用其中一种

题型:阅读理解

在链式存储结构中,用()来体现数据元素之间逻辑上的关系。

题型:阅读理解
一物体静止在地面上,在竖直方向的拉力作用下开始运动(不计空气阻力)。在向上运动的过程中,物体的机械能E与上升高度h的关系图象如图所示,其中O-h1过程的图线是过原点的直线,h1-h2过程的图线为平行于横轴的直线。则(   )

A.在O-h2升过程中,物体先做加速运动,后做匀速运动

B.在O-h1上升过程中,物体的加速度不断增大

C.在O-hl上升过程中,拉力的功率保持不变

D.在h1-h2上升过程中,物体只受重力作用

题型:阅读理解

短轴褶曲

题型:阅读理解

残余应力指工件在没有外力作用,且各部位也没有温度差的情况下而存留于工件内的应力。()

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