问题 选择题

下列命题中是真命题的是(  )

A.对角线互相垂直且相等的四边形是正方形

B.有两边和一角对应相等的两个三角形全等

C.两条对角线相等的平行四边形是矩形

D.两边相等的平行四边形是菱形

答案

A、错误,例如对角线互相垂直的等腰梯形;

B、错误,不能确定;

C、正确,符合矩形的判定定理;

D、错误,两边相等的平行四边形是平行四边形.

故选C.

阅读理解

China’s first moon rover,Yutu,or Jade Rabbit,separated from the lander early on Sunday,December l5,2013,several hours after the Chang’e-3 probe (探测器) soft-landed on the lunar surface.The l 40 kg six-wheeled rover touched the lunar surface at 4:35 a.m.,leaving deep trace on the loose lunar soil. The process was recorded by the camera on the lander and the images were sent to the earth,according to the Beijing Aerospace Control Center.

After the separation,the rover and lander will take photos of each other and start their own scientific explorations. Engineers made final checks of the environment of the landing site,the situation of the probe and sent signals of separation to Chang’e-3.

Yutu, on the top of the probe,extended its solar panel and started to drive slowly to the transfer mechanism (机械装置) at 3:10.The transfer mechanism unlocked at 4:06 with one side reaching the moon’s surface,allowing the rover to descend to the surface following a ladder mechanism.

Chang’e-3 landed on the moon’s Sinus Iridum,or the Bay of Rainbows,at 9:11 p.m.Saturday,making China the third country in the world to carry out such a rover mission after the United States and former Soviet Union.

In ancient Chinese mythology,Yutu was the white pet rabbit of the lunar goddess Chang’e.The name for the rover was selected following an online poll that collected several million votes from people around the world.

The rover,1.5 meters long with its two wings folded,1 m in width and l.1 m in height,is a highly efficient robot controlled by the command center from the earth.It will face challenges including temperature differences of more than 300 degrees Celsius on the moon.

Yutu will survey the moon’s geological structure and surface substances and look for natural resources for three months,while the lander will conduct in-situ (现场) exploration right at its landing site for one year.

小题1:What’s the passage mainly about?

A.China’s first moon rover,Yutu,touched the lunar surface.

B.The rover and the lander took photos of each other successfully.

C.Chang’e-3 landed on the moon’s Sinus Iridum, or the Bay of Rainbows.

D.Yutu will survey the moon’s geological structure to find substances.小题2:Which of the following show the correct order of the Yutu’s landing?

a.drive to the transfer mechanism   b.extend its solar panel   c.follow a ladder mechanism      

d.descend to the surface          e.unlock the transfer mechanism

A.e→b→a→c→d

B.a→b→e→d→c

C.b→a→e→c→d

D.c→a→b→e→d小题3:We can learn from the last two paragraphs that          .

A.Yutu’s two wings are l.5 meters long and l meter wide

B.Yutu will explore the moon right at its site for one year

C.Yutu will get out of the earth command center’s control

D.Yutu can bear great temperature differences on the moon