—I’m going to attend your lecture at 9∶30 tomorrow morning.

—I regret to tell you that. When you arrive, it will have ended and I ________ questions with my students.

A．would discuss

B．will discuss

C．will be discussing

D．am discussing

普通钢材( )代替锅炉压力容器钢材。

A．不能
B．可以
C．在一定条件下可以
D．不限制