There are over 58000 rocky objects in space，about 900 of which could fall down onto earth.
A. the; the
B. /; the
C. the; /
D. a; the
网友回答
A. the; the
(答案→)B. /; the
C. the; /
D. a; the
解析：考查冠词。第一空后的space是抽象名词，要单独使用；第二空the earth指地球；句意：在太空里有58000个岩石的物体，大约900个可能会落到地球上。故B正确。