——What a heavy rain！ Will it last long?

—— ________ . We are getting into the rainy season now.

A．Of course not

B．I′m afraid so

C．That′s impossible

D．I′m afraid not

平屋顶和斜屋顶的坡度区分界限值是( )。

A．2%

B．6%

C．10%

D．12%