问题
单项选择题
Directions: There are 10 blanks in the following passage. For each numbered blank, there are four choices marked A, B, C and D. Choose the best one and mark your answer on the ANSWER SHEET with a single line through the center.
| Our planet is like a bit spaceship. Our atmosphere acts (51) a shield against harmful radiation and space debris. (52) holds the air and people on the spaceship, (53) everything doesn’t float away. Each of us is an astronaut and our spaceship, the earth, provides our food and water. The sun is our energy (54) and without it we would not be able to survive. (55) every spaceship, the earth is a closed system. The only thing we receive from the outside is energy from the sun. Everything else must be used (56) again. We astronauts don’t seem to realize that this spaceship is the (57) one we’ve got. We (58) its resources and waste the energy the plants have stored from the sun. If we (59) our spaceship, we will destroy ourselves as well. Maybe if we look at the universe which surrounds us, we will appreciate our own spaceship more and take (60) care of it. |
A．unless
B．even if
C．in case
D．so that
答案
参考答案：D
解析： “一切不会飘离地球而去”是地球引力把人和物都吸引住了的结果，故应选表示结果的连词so that，引导结果状语从句。unless意为“除非”，even if意为“即使”和in case意为“如果，万一”都不符合题意。