止回阀的驱动方式是().
A.流体作用
B.手动
C.力水液压传动
D.机械作用传动
参考答案:A
—Is David a man with good manners ?
—I don’t think so . As a matter of fact , he is _____but polite .
A.something
B.everything
C.nothing
D.anything
养老穴擅治下列哪种疾病()
A.呃逆
B.风疹
C.痛经
D.腿痛
E.落枕