把50克盐放入200克水中，这时盐和水的重量比是1：4．______．
50：200=1：4，
故答案为：√．
解方程：
1-0.85x=0.15
1.6x-0.68x=0.184
1.2×5+5x=6.6．
— This is Janine speaking.
— Janine, I want to tell you Pat _____ for London. Have you decided to see him off? [ ]
A. left
B. has left
C. is leaving
D. was leaving
