呈方块状或圆柱状，棕黄色，质硬，气微腥，味苦的是（）

A.制天南星

B.水半夏

C.胆南星

D.清半夏

E.姜半夏

An advantage of an ABC dry chemical over a carbon dioxide extinguisher is（）.

A.lack of toxicity

B.the multipurpose extinguishing ability

C.burn-back protection

D.cooling ability