I was told ________ Bill Gates was thirteen he began to play with computers.

1. A.
   that how
2. B.
   how that
3. C.
   when that
4. D.
   that when

A. that, how　　   B. how, that　　　　  C. when, that　　　　  D. that, when

I was told         Bill Gates was thirteen he began to play with computers.

A．that how   B．how  C．when that D．that when