To telephone him, you will have to（ ）his number in your phone bo

To telephone him, you will have to（ ）his number in your phone book.

look to 

look up

look through

look at

A.look to：指望；B.look up：查阅；C.look through：逐一查看；D.look at：看，选B。句意：打电话给他，你得在电话簿上查他的号码。