为了排除雨水，土石坝的坝顶应做成向一侧或两侧倾斜的横向坡度，坡度宜采用( )。
A．1%～2%
B．2%～3%
C．2%～4%
D．3%～4%
参考答案：B
China is one of________ countries in the world.
A．the largest
B．the larger
C．the large
D．larger
