mushroom可數(shù)嗎

　　例句：

　　How big the mushroom is!

　　這朵蘑菇真大呀！

　　Let's drink some mushroom soup first.

　　先喝點蘑菇湯吧。

　　I'd like a large pizza with peppers and mushroom, please.

　　請給我一個大比薩，上面放胡椒和蘑菇。