There are many CD-ROMs in the bookshop. I don’t know ____ to buy.

Yesterday I was late _____ school because the traffic was heavy. [ ]

Who’s the man over there?Is it Mr. Black?——It______be him. He’s much taller.

She was more famous __________ a writer than __________ a singer.[ ]

What can they do? —-They can teach _________Chinese.