某些机场的中转手续要到所换航班指定的候机室办理。
参考答案：对
既能退虚热，又可清热燥湿的药物是( )
A．黄芩
B．知母
C．苦参
D．黄连
E．胡黄连
—Have you ever been to London?
—Yes, I have been there _______ 2000.[ ]
A. for
B. after
C. since
D. in
