自然灾害救助
参考答案：
是国家和社会为遭受自然灾害袭击而生活无着落的公民提供紧急救助，以保证公民维持最低的生活水平。
It _____we had stayed together for a couple of weeks ______ I found we had a lot in common. [ ]
A. was until; when
B. was until; that
C. wasn't until; when
D. wasn't until; that
简述匀染剂与防泳移剂的相同点和不同点。
