1. I am not sure whether I want to take this course;_______________(我第一周可否旁听)to see if I like it?
　　2. The police are on the trail of new evidence _______________(希望能有助于该案的处理).
　　3. The volume of trade between the two countries,as is reported,________________(增长了三倍多).
　　4. My question is _______________(谁将接任该基金会主席职位).
　　5. He looks honest,but ________________(外表有时是靠不住的),aren’t they?

　　答案与解析：
　　1. may I sit in for the first week
　　2. which they hope will help solve the case
　　3. has increased more than fourfold
　　4. who will take over as president of the Foundation
　　5. appearances are sometimes deceiving