练习：
1.A but B if C though D while
2.A personality B movement C emotions D will
3.A privately B usefully C awfully D personally
4.A looked for B looked at C looked after D looked up
5.A favorite B trustful C boring D annoying
6.A with B on C by D at
7.A professors B participants C assistants D scientists
8.A group B class C section D part
9.A Previously B Formally C Initially D Finally
10.A remember B explain C rewrite D complete
11.A sad B secure C shy D angry
12.A your B our C his D their
13.A accident B harm C experience D model
14.A eating B exchanging C buying D keeping
l 5.A expressions B estimation C cooperation D connections