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问题 单项选择题

吗啡的镇痛作用机制是

A．抑制中枢PG的合成
B．抑制外周PG的合成
C．阻断中枢的阿片受体
D．激动脑室及导水管周围灰质等部位的阿片受体
E．减少致痛因子的产生

答案

参考答案：D

单项选择题

原发性肝癌的早期转移途径为

A．淋巴转移

B．肝内血行转移

C．肺内转移

D．腹膜后转移
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选择题
—What would you like to do after finishing your education, Bruce?
—I'd like to work ______.

A. as quickly as I do
B. so early as I can
C. as good as possible
D. as soon as possible
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