Question

【题目】It was not until 1920 _____ regular radio broadcasts began.

A. which B. when C. that D. since

Answer 1

【答案】C

【解析】考查强调句式。强调句式由“It is/was+被强调成分+that/who…”构成。当被强调部分指人时，连词用who，当被强调部分指物时，连词用that。