There are over 58,000 rocky objects in_____ space,about 900 of which could fall down onto ______ earth.
A.the;the | B.不填;the | C.the;不填 | D.a;the |
There are over 58,000 rocky objects in_____ space,about 900 of which could fall down onto ______ earth.
A.the;the | B.不填;the | C.the;不填 | D.a;the |