________ he is a child, ______ he knows much about the computer.

By the first day of August, 2007, the PLA ________ for eighty years.

They were invited to an important ball ____ the first time ____ their lives. [ ]

Mr Green, do you know_______? ——July 10,It will last a month.

Yao Ming was born _____ September 12,1980. [ ]