16、The researchers determine what type of plants the virus can infect（感染） and       insects can carry the virus．

A．those           B．why        C．which         D．how

15、At last, the boys found themselves in a pleasant park with trees providing shade and     down to eat their picnic lunch．

A．to sit        B．sat           C．sitting          D．having sat

14、He spent much of the evening with Robert Green,        he had hardly seen in the thirty years since they had worked together at CBS．

A．what            B．that          C．who          D．whom

13、Mr. Brown arranged for the taxi to come at six       she would not have to wait long at the station．

A．so that          B．even if           C．before          D．because

12、People aren’t watching      television as before on Christmas Day because they use their videos．

A．too much        B．too many          C．as much         D．as many

11、Children above 12 are able to take part in skiing or other activities        for them．

A．having designed            B．designing     C．to design         D．designed

10、Peter was sure that      he drank any more of this good red wine he would fall asleep．

A．if           B．when           C．as          D．since

9、Unemployment is on the increase．A growing number of young people,       , are finding themselves out of work．

A．in case           B．all in all          C．in particular           D．as a result

8、About seven years ago she felt she had to ask herself      she really wanted to spend her life farming．Now she has make up her mind to quit farming．

A．when         B．whether          C．what          D．where

7、I feel sorry for those young people who don’t care for their aged people       mine．

A．as I do care          B．do as I care          C．do as I         D．as I do