测定酸值时,自锥形瓶停止加热到滴定达到终点,所经过的时间不应超过()分钟。
A.5
B.3
C.1
D.4
参考答案:B
_____ children believe they can succeed, they will never become totally independent. [ ]
A. If
B. Though
C. Unless
D. When
刺激性气体的刺激反应不包括( )
A.眼结膜充血、流泪 B.流鼻涕、打喷嚏C.接触性皮炎 D.咽痛、咽部充血