污水处理厂的处理效率，二级处理活性污泥法BOD5去除率为（）。
A.70％～90％
B.65％～95％
C.70％一95％
D.60％～90％
参考答案：B
The film The Flowers of War, which ______ last December, is about saving a group of Chinese students in the 1930s.
A．worked out
B．came out
C．turned out
D．broke out
蛙泳的减阻为什么比其他泳式更为重要？
