Question

【题目】_____ people have done lots of research on moon, there is still much waiting to be discovered.

A. If B. Since C. Because D. Though

Answer 1

【答案】D

【解析】

句意：——尽管人们已经在月球上做了许多调查，还有很多有待发现的地方。A. If如果；B. Since自从；C. Because因为；D. Though尽管。根据下文there is still much waiting to be discovered可知上文是Though引导的让步状语从句。根据题意，故选D。