Question

It was only after World War II had drawn to a close ______ in the United States.

A．did the baby boom begin	B．that the baby boom began
C．when the baby boom began	D．then the baby boom began

Answer 1

B

试题分析：：考查强调句型。本题考查强调句型：it is/was被强调成分that/who…；强调句型的最大特点是把it is/was…that/who…去掉句子仍然成立。本题强调的是主语only after World War II had drawn to a close句意：只有在第二次世界大战结束后，美国人口出生快速增才开始。故B正确。
点评：本题考查强调句型：it is/was被强调成分that/who…；强调句型的最大特点是把it is/was…that/who…去掉句子仍然成立。这题不要和only+状语+倒装句混起来，因为只有only+状语在句首才倒装。