某化学兴趣小组的同学用右图探究质量守恒定律，结果测得反应前后质量不相等．他们更换药品后重新实验，得出了正确的结论．他们选用的试剂是（　　）

根据生活经验和所学知识判断，下列课外实验不能成功的是（　　）

先通读下面的短文，然后根据短文内容和所给首字母，在空格内填入一个适当的词，使短文意思完整。
    Mental health is about the way you think and feel and your ability to deal with ups and downs. Even though you are mentally healthy, it hardly m ____ that you don’t have a mental health problem.
    Mental health is everyone’s b____ . We all have times when we feel down or stressed. Most of the time those feelings pass, but sometimes they develop into a more serious problem. It seems that our mental health doesn't always s____  the same. It can change as the environment changes and as you move t ____ different stages(阶段) of your life.
    Here are four practical ways to look after your mental health. M ____  simple changes to how you live doesn't cost much or take up lots of time. Anyone can f ____ them.
●Talk about your feelings. It can help you stay in good mental health. It isn't a sign of weakness, but p ____ of your ability to do what you can to stay healthy.
●Eat well. What you eat and how you feel are c ____  connected. A proper diet can have a good effect on your mental health.
●Keep in touch. Friends and family members can offer various a ____  which may help you keep active and solve practical problems.
●Take a break. It could be a weekend exploring new places to enjoy the nature, or even a ten-minute break from doing your homework. A few minutes can be e____ to relax you.

读“影响我国的季风示意图”及“我国东部部分城市气候类型图”，回答问题