可引起股骨头无菌性坏死的药物中最常见的是
A．氯喹
B．雷公藤
C．甲氨蝶呤
D．糖皮质激素
E．长春新碱
参考答案：D
用所给词的适当形式填空。
1. Do you learn English by _____ (watch) English-language videos?
2. What about _____ (listen) to tapes?
3. We get _____ (excite) about something.
4. Do you know the best way _____ (learn) English?
5. He finds watching English movies _____ (frustrate).
临时反倾销或反补贴措施，实施期限为自决定公告之日起，不超过( )。
A．3个月内 B．6个月C．4个月 D．9个月
