某水样pH值为12，采用单项指数法评价的标准指数为（）。
A.0.71
B.0.50
C.2.50
D.4.00
参考答案：C
The river______ surface used to be covered with waste and rubbish is now taking on a new look.
A．of which
B．along with
C．where
D．whose
以买卖方式转让房地产时，同等条件下什么人有优先购买权？
