根据酸碱质子理论，以下关于水的叙述正确的是（）。

A、水是酸

B、水是碱

C、水既是酸又是碱

D、水既不是酸也不是碱

What is the expectation of overall summer travel this year().

A.A 2.5% rise.

B.It would rise along with international tourism.

C.A28% rise.

D.Patriotism would not be a theme in travel market.