基本信息
1．it________mike and mary who helped the old man several days ago.
a．was b．are
c．were d．had been
[解析] 本题考查的是强调句式。强调句式由“it is/was＋被强调成分＋that/who…”构成。由于句中的动作是发生在过去，故选a。
[答案] a
2．it was not until 1920________regular radio broadcasts began.
a．which b．when
c．that d．since
[解析] 本题考查的是强调句式。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，可用who，当被强调部分指物时，用that。
[答案] c
3．she said she would go and she________go.
a．didn’t b．did
c．really d．would
[解析] 在谓语动词前加do表示对动作的强调。and连接两个并列谓语，其形式应一致，故用过去时态。
