My brother          with his friends tomorrow if it          .            [ ]

A. is going to hike; won't rain            

B. is going hiking; doesn't rain            

C. will go hiking; won't rain            

D. goes hiking; doesn't rain

下列关于乙酸的说法中正确的是  [ ]

A．乙酸是有刺激性气味的液体

B．乙酸分子中含有4个氢原子，它不是一元羧酸

C．乙酸在常温下能发生酯化反应

D．乙酸酸性较弱，不能使石蕊试液变红