患者神疲乏力，少气懒言，常自汗出，头晕目眩，舌淡苔白，脉虚无力。其证候是
A．气虚
B．气陷
C．气逆
D．气微
E．气滞
参考答案：A
-- How did you find your trip to Huangshan?
-- ______ .
A．I went there by air
B．A friend took me there
C．Wonderful indeed
D． In a travel book
流行病学探索病因的一般程序是
A．从人为关联到统计学关联
B．从统计学关联到因果关联
C．从间接关联到统计关联
D．从人为关联到因果关联
E．从间接关联到因果关联
