The scientists began to think about what use could be __such things.

题目

The scientists began to think about what use could be __such things.
A made up B made from C made of D made out

答案

还原成主动语态就容易看清楚了,（scientists）made use of such things,这样 你就看出来“利用”只能是make use of而不能是其他介词了.
科学及们开始思考这（种）事物能够有何用处/可以如何利用.