Question

【题目】In the past, most children couldn't go to school poor economy（经济）.
A.because
B.because of
C.since
D.for

Answer 1

【答案】B
【解析】句意：过去，大部分孩子们由于贫困的经济而不能上学。because因为，后跟从句；because of因为，后跟名词。since既然，跟从句；for因为，跟从句。poor economy是名词短语，所以答案是B。