下列各项对氢氧化钠的描述正确的是( )①是一种有色晶体,易溶于水,溶解时放出大量的热②固体氢氧化钠置于空气中易潮解③氢氧化钠水溶液使石蕊溶液呈红色④对皮肤、衣服等有强烈的腐蚀性⑤氢氧化钠在空气中不仅吸收水分,还和二氧化碳反应
A:①②④⑤
B:②④⑤
C:①②④
D:④
如图是课堂上所学得的物理知识.
- Junior high school days will be over _______ a week. How are you feeling?
- I'm trying to keep my cool because we've been together ________ three years.