完形填空：

阅读下面短文，掌握其大意，然后从1～10各题所给的四个选项中，选出一个最佳答案．

　After the end of the Second World War, the Russians became very interested in space science, and they sent several rockets up above the air. The earth is surrounded by air, but this air doesn't stretch (延伸) upward for more than a few hundred miles, and 　1 　only about ten miles the air is so thin that no ordinary plane will fly in it. To go higher it is necessary to use a rocket, which will work excellently even when moving in outer space. The first rockets 　2 　into space carried no astronauts but scientific instruments (仪器), the next carried animals and when they were brought safely to the earth, the Russian scientists 　3 　a man. They chose Yuri Gagarin to be the pilot.

　Flying a space ship is 　4 　flying an ordinary plane. Instead of sitting at the controls, the pilot lies upon a couch (睡椅).

　The spaceship was travelling 　5 　5 miles a second—faster than any man travelled before. Gagarin did not get any feeling for the speed, and he could 　6 　the small round window of the cabin (船舱).

　Gagarin was busy doing scientific experiments. Before long the spaceship passed into the Earth's Shadow. When it came out of the shadow again, the horizon (地平线) showed a bright orange colour. In space the sky looked black even when in the sunlight. It is only from the earth 　7 　the sky looks blue. When we look at the sky, we see the sunlight lighting up the air all around the earth. The air has 　8 　the other colours in sunlight, but reflects (反射) the blue light, which we see. In space there is no air to split up the sunlight.

　Now, it was time for Gagarin to prepare for landing. This was perhaps the most dangerous part of the whole trip. If he came into the air too quickly, his ship would 　9 　the air, and this would make the ship so hot that it would burn up. The speed of the spaceship had to be controlled.

　The spaceship dropped closer and closer to the ground until, when not far from the ground, Gaggrin's cabin 　10 　the rest of the rocket. Then the cabin, together with Gagarin, flew gently down to a safe landing.

　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　 　　

(1)A． above a height of	B． between a length of
C． over a width by	D． about a thickness with	[　　]
(2)A． send off	B． sent out
C． sent up	D． send forth	[　　]
(3)A． was eager to launch	B． were anxious to let fly
C． was prepared to send out	D． were ready to send up	[　　]
(4)A．as the same as	B． not the same as
C． not as same as	D． no same with	[　　]
(5)A． at the speed of	B． with the speed for
C． at a speed of	D． in a speed to	[　　]
(6)A． look out	B． look through
C． look for	D． look after	[　　]
(7)A． that	B． in where
C． from where	D． which	[　　]
(8)A． some effect on	B． no effect to
C． no effect on	D． not any effect in	[　　]
(9)A． beat down	B． strike at
C． hit into	D． rub against	[　　]
(10)A． was separated from	B． were separated for
C． was separating from	D． were separating with	[　　]