1.We are happy to have our () holiday,because seven days () a long time to have a picnic.

题目

1.We are happy to have our () holiday,because seven days () a long time to have a picnic.
A.seven-days;is B.seven-day;is C.seven-day;are D.seven-day's;are
我认为是C,但答案是B,不知为什么
2.I wabder if I can ask him () time.
A.four B.fourth C.the fourth D.a fourth
我认为是C,但答案选D,不知为什么

答案

1.B.
英语语法中规定,如果是时间/金钱/重量/距离等做句子主语时,其视为一个整体,谓语动词必须用单数形式.
再如：Ten years is a long time.
2.D
the fourth time不能单独做状语,必须改成for the fourth time“第四次”；
而a fourth time意思是“又一次/再一次”,可以单独做状语.