若使接近饱和的硝酸钾溶液变成饱和溶液可采取哪些方法?
参考答案:
①降低温度;②蒸发水分;③在加入硝酸钾晶体.
Look at the young men. They _____ the bus.
A.are running for
B.are run
C.is running
D.run for
居民医疗保险筹资水平?