下列动物体温比较恒定的一组是：　　　　　　　　　　　　　　　　[ ]

A．蛇和麻雀

B．狼和家鸽

C．鲸和鲫鱼

D．虎和青蛙

.

They want to employ 90 people, __________last year.

A．three times as many as

B．more than three times

C．as three times as

D．three times that they did