The world lost seven astronauts of Space Shuttle Columbia(哥伦比亚号航天飞机) thismonth. It brought home the serious risk that 1 face into the hostile environs beyond our 2 planets, raising the question of 3 exploring the heavens should be left to unmannedmissions.4 less exciting, such missions will 5 no risks to humans. And alreadyrobots have an impressive list of accomplishments 6 to their flesh and blood counterparts(职级地位相当的人或物)。

　　“ 7 are all about specifically targeted scientific 8 of the universe around us.Without exceptions, these efforts rise out of intense competition 9 the most compelling,and answerable questions are 10 ,” said Marc Buie, an astronomer (天文学家) at LowellObservatory in Flagstaff, Arizona.11 have dug in the dirt on Mars, flown in the 12of Jupiter (木星)， and driven by the moons of Neptune. A few are13approaching the boundary of the 14.

　　Humans, 15 , have mostly been going in circles, 16 above the surface of theplanet.17 the brief Apollo Mission triumphs on the 18 , almost 250,000 milesaway, humans have 19 gone farther than 400,000 miles from the planet, less than aday´s drive, although straight up. Humans fly near home for several reasons. There is thelogistics(后勤) of sending humans and what they need, like water, air and food, in a closedenvironment that keeps them 20.

　　1. A) humans B) stars C) planets D) robots

　　2. A) enclosed B) screened C) isolated D) sheltered

　　3. A) whether B) why C) if D) that

　　4. A) Moreover B) If C) But D) As

　　5. A) provide B) pose C) put on D) perform

　　6. A) related B) contrasted C) compared D) referred

　　7. A) Unmanned missions B) Space Shuttle Columbia

　　C) Space tours D) Apollo Mission

　　8. A) expeditions B) explorations C) investigations D) researches

　　9. A) which B) that C) where D) as

　　10. A) put B) suggested C) posed D) raising

　　11. A) Robots B) Humans C) Astronauts D) Astronomers

　　12. A) sky B) heavens C)moons D) atmosphere

　　13. A) also B) even C) still D)only

　　14. A) universe B) solar system C) space D) moon

　　15. A) consequently B) hence C)at any rate D) on the other hand

　　16. A) seldom B) never C)barely D) almost

　　17. A) Besides B) Except C) Excluding D) Other than

　　18. A) Mars B) moon C) planet D) Jupiter

　　19. A) never B) seldom C) once D) ever

　　20. A) safe B) warm C) alive D) active

　　
　答案解析：

　　1.A。毫无疑问，这里指人类面对充满险恶的茫茫宇宙。

　　2.D。与地球外的空间相比，地球相对安全，因为它受到了大气等的保护，因此D项“受庇护的，受保护的”最恰当;A项意为“围住的，圈起的”，B项意为“被(光，风等)遮蔽的，被屏蔽的”，C项意为“孤立的”，均不如D恰当。

　　3.A。通读全文可知，本文讨论的是是否应该让机器人代替人类进行宇宙探索，因此这里应该选A;if 虽然也有“是否”的用法，但不能与介词of连用。

　　4.A。这句话的意思是“用机器人代替人类进行的太空任务减少了许多魅力，__________它不会给人类造成危险”;将四个选项逐一填入，可发现此句没有递进、假设或因果关系，而是存在转折关系，因此选A。