Susan, _______ university student from Europe, teaches me _________ art in her spare time.

A．an; /

B．a; the

C．an; the

D．a; /

与反气旋有关的下列描述中不正确的是（）

A.气流顺时针方向旋转

B.风速大

C.阻止污染物向上扩散

D.天气晴朗

E.出现逆温