Unless astronomers ______ their search for extraterrestrial life to stars as exceptional as the Sun, they are wasting much of th

admin2011-05-29  29

问题 Unless astronomers ______ their search for extraterrestrial life to stars as exceptional as the Sun, they are wasting much of their time.

选项 A、narrow down
B、boil down
C、tone down
D、let down

答案A

解析
转载请注明原文地址:https://kaotiyun.com/show/Et6O777K
0

随机试题
最新回复(0)