丙烯酰胺室温下稳定，在熔融时能突然聚合。
参考答案：对
My mother _________lots of things and took the subway back home yesterday.
A．buys
B．bought
C．is buying
D．is going to buy
国际法的主体（）是国家
A.主要
B.只能
C.不能
D.仅限于
