We can use QQ to talk with each other online.

       --Good! Will you please show me ______it?

A.what to use    B.how to use    C.when to use    D.where to use

We can use QQ to talk with each other online.

       --Good! Will you please show me ______it?

A:what to use    B:how to use    C:when to use    D:where to use

—We can use QQ to talk with each other online.
—Good! Will you please show me ______it?

1. A.
   what to use
2. B.
   how to use
3. C.
   when to use
4. D.
   where to use