国家开放大学 / 综合英语（3）
正确率：100%
The aftershocks of the quake can give scientists some help _ _ _ _ _ _ where these hidden fault lines are.
A.to cave in
B.in mapping out
C.in monitoring
D.to get stuck in
A.to cave in
B.in mapping out
C.in monitoring
D.to get stuck in
参考答案：
佳题速递：