常用的定价策略有哪些？（）
A.商品组合定价
B.差别定价
C.心理定价
D.折扣定价
参考答案：A, B, C, D
骶棘肌痉挛征常见于（）
A.股骨头骨软骨病
B.髌骨软骨软化症
C.疲劳骨折
D.滑囊炎
E.腰肌劳损
What would have happened ________，as far as up to the river bank.
A．Bob had walked farther
B．if Bob should walk farther
C．had Bob walked farther
D．if Bob walked farther
