刚性水池的池壁一般采用（）池壁。
A、垂直形
B、内倾形
C、外倾形
D、下宽上窄形
参考答案：A
The pilot kept calm in the terrible storm, otherwise the accident ______.
A．couldn’t be prevented
B．mustn’t have prevented
C．wouldn’t have been prevented
D．shouldn’t prevent
既能降气化痰，又能宣散风热的药物是
A．前胡B．白前C．旋覆花D．杏仁E．苏子
The pilot kept calm in the terrible storm, otherwise the accident ______.