With the World Cup at hand, _______ has been a heated discussion over which country the championship will go to.

A．it

B．what

C．there

D．as

变换催化剂进水可能是由于（）。

A、提高变换炉温度

B、提高操作压力

C、饱和塔液位超高

D、停车塔未排水