英语选修7北师大版同步作业及答案：Unit 19（3）语言点
Ⅰ.完成句子
1．To make sure that he was at home, I called him up in_advance (事先)．
2．She may come with us provided_that (假如) she arrives in time.
3．In_addition (除了) to these arrangements, extra ambulances will be on duty until midnight.
4．The discussion focused_on (集中于……) three main problems which drew attention of most people.
5．Come and sign_up (报名), and you will get a great chance.
Ⅱ.单项填空
1．All their attention w
