化学小组的同学们准备制取氧气.实验室现有双氧水、二氧化锰,以及下列仪器:
下面是一些常见的避震减灾的方法,你认为最不安全的做法是( )
The Greens ________live in the south of Asia . They don't want to move to the north because they ________ the cold weather.