表明城市的共性，是区分城市与乡村的依据，这是城市的（）。
A.主导功能
B.综合功能
C.一般功能
D.特殊功能
参考答案：C
如图所示是一列波的波形图，波沿x轴正向传播，就a、b、c、d、e五个质点而言，速度为正，加速度为负的点是（ ）
A．b
B．a
C．d
D．c
The new stadium being built for the next Asian Games will be ________ the present one.
A．as three times big as
B．three times as big as
C．as big as three times
D．as big three times as
