Life is full of _______.School is thought as the most _______ obstacle(障碍) in the lives of youth today.
| A.challenge; challenging | B.challenges; challenged | 
| C.challenges; challenging | D.challenging; challenges | 
Britain has recently had a high level of unemployment—but the same is true ________ many other countries.
| A.at | B.from | 
| C.of | D.to | 
—I’m going to cut the big tree down? —What ________ ?
| A.by | B.to | 
| C.with | D.at | 
So far, several ships have been reported missing ________ the coast of Bermuda.
| A.off | B.along | 
| C.on | D.around | 
________ her hair getting gray, she has decided to have it dyed.
| A.As | B.For | 
| C.With | D.Though | 
—I like coffee with nothing in it. What about you? 
 —I prefer coffee ________ sugar.
| A.to | B.for | 
| C.with | D.than |