影响烟叶吸湿性的外部因素有：（）
A.烟草自身的性质
B.空气温度
C.空气湿度
D.空气流速
参考答案：B, C, D
下列血气非常正常值的是（）
A.PO250~70mmHg
B.BE-3~+3
C.pH7.35~7.45
D.PCO223~45mmHg
E.HCO3-22~27mmHg
— You look _______. Can you tell me why you are so happy?
— Sure. There will be anther _______ relay race in the afternoon. [ ]
A. excite; exciting
B. excited; exciting
C. exciting; excited
D. excited; excite
