外感风邪所致头痛最宜使用（）
A.羌活胜湿汤
B.镇肝熄风汤
C.川芎茶调散
D.龙胆泻肝汤
E.半夏白术天麻汤
参考答案：C
一个工人用如图所示的滑轮组匀速提升2000N的货物，所用拉力为600N，绳子自由端被拉下4m．求：
（1）此滑轮组的机械效率多大？
（2）你认为此滑轮组的机械效率与哪些因素有关？
He moved away from his parents, and missed them （）to enjoy the exciting life in New York.
A. too much
B. very much
C. enough
D. so much as
