一、单项选择（共30小题，计30分）
1.--- Shall we call a taxi?
---- Ok, Let me ______ the phone number in Yellow Pages.
A. look at B. look for C. look up D. look after
2. The math problem is so hard, I really don’t know _____.
A. how to do it B. how to do C. what to do it D. when to do
3. ---I have trouble _____ my new computer.
-----Don’t worry. I’ll show you how ____it.
A. using, using B. to use, to use C. using, to use D. to use, using
