题目

Space suits don’t just make astronauts look cool. Without these ______ suits, astronauts wouldn’t be able to leave their spaceship. That is to say, they wouldn’t be able to ______ on the Moon or work outside the International Space Station.Space is a ______ place for human beings. Firstly, there is no air to breathe. Secondly, space also has high levels of radiation(辐射), energy that can pass through our bodies and make us ______. Thirdly, some parts of space are really cold ______ other parts are very hot. So astronauts could die in just a few seconds if they ______ outside their spa湘江是我们的“母亲河”，为了让市民喝上放心水，政府坚持加大力度治理，水质得到明显改善，请回答下列问题：（1）检查湘江水是硬水还是软水，可用的物质是_______；（2）生活中硬水软化的方法是________；（3）为保护“母亲河”，请你提出一条防治水污染的建议：_________。