The other day my brother drove his car at ________ I thought was dangerous speed.

A. as 　　　　 B. which　　　　 C. what　　　　　 D. that　　　　 (上海 2004)

The other day，my brother drove his car down the street at ________ I thought was a dangerous speed. 　　　　　　　　　　　　　　　　　　　 (上海春招 2004)

A. as　 　　　 B. which C. what　 　 D. that