The professor said he could talk on _____ interested the audience.

A．any topic

B．which topic

C．whichever topic

D．the topic he thought it

我国年降水量分布的总趋势是[ ]

A、由西北向东南递减　　　　　　　　　

B、由南向北逐渐减少

C、由东北向西南减少　　　　　　　　　

D、由东南沿海向西北内陆递减