水中的盐类均以（）的形式存在。
A.原子
B.分子
C.离子
D.颗粒
参考答案：C
It’s common sense that in summer people like to seek shade the air is cooler.
A．in where
B．in which
C．where
D．the place where
He has been late three times_____the morning of last Friday. [ ]
A. in
B. on
C. since
D. Until
