用化学用语表示：

（1）5个磷原子______；硝酸铝______；最高价硫元素的氧化物______；不含金属元素的碱______．

（2）根据下列要求写出相关的化学反应方程式：

双氧水和二氧化锰混合制氧气：______；

用烧碱溶液来吸收二氧化硫气体：______；

湿法炼铜：______；

用一氧化碳还原磁铁矿：______．

Optimism is the art of always seeing the glass half full (1) half empty, finding something positive in even the most (2) of situations and last but not least the ability to expect the best even if the chances are (3) . It enables you to try new things, deal with failure as a learning experience (4) a stopping point. In general optimism gives you a reason to live. The world would be a better place if it was full of optimism, (5) unfortunately the trend in today’s youth is (6) the opposite way. Today it is (7) to be pessimistic. One could spend hours discussing how we arrived at this point, (8) our youth refuses to smell the roses and instead prefers to (9) themselves on their own pessimistic (10) .

Optimism is not an (11) gift but rather a learned behavior (12) . Like most behaviors optimism is best learned by watching examples, (13) you. The first step in creating a generation of people with a positive outlook on life, is to (14) life on the bright side yourself. (15) it would be wrong to (16) your child from all negativity, it is important that you are not the (17) of doubts and worries. Finding something positive in a negative situation needs to be (18) Show how to make the best of things by always (19) the positive, by encouraging your child after a(n) (20) and by explaining over and over that failure is just a part of progress.

16（）

A.shelter

B.free

C.isolate

D.nurture