There were some chairs left over________everyone had sat down.
| A．when | B．until |
| C．that | D．where |
Before you pay a visit to a place of interest, look in your local librarya book about it.
| A．on | B．at | C．for | D．to |
From space, the earth looks blue. This is about seventy-one percent of its surface is covered by water.
| A．why | B．how | C．because | D．whether |
--- You needn't take an umbrella. It isn't going to rain.
--- Well, I don't know. Itdo.
| A． | might | B． | need | C． | would | D． | should |
If wea table earlier, we couldn’t be standing here in a queue.
| A．have booked | B．booked | C．book | D．had booked |
Experts believepeople can waste less food by shopping only when it is necessary.
| A． | why | B． | where | C． | that | D． | what |