I think it is i____ for children to learn how to do c____ and help their parents with housework. It's not enough to just get good grades at school. Children these days d____ on their parents too much. They're always a____ “Could you get this for me?” or “Could you help me with that?” Doing chores helps to d____ children's independence and teaches them how to look after themselves. It also helps them to understand the idea of f____. S____ they live in one house with their parents, they should know that everyone should do their part in k____ it clean and tidy. Our neighbor's son got into a good college but during his first year, he had no idea how to take care of himself. As a result, he often fell ill and his grades d____. The earlier kids learn to be i____ the better it is for their future.

金属镍有广泛的用途，粗镍中含有少量Fe、Zn、Cu、Pt等杂质，可用电解法制备高纯度的镍，下列叙述正确的是（已知：氧化性Fe^2＋<Ni^2＋<Cu^2＋）