单词拼写（共10小题，每小题1分，满分10分）
Some metals expand when it is hot and c_____ when it is cold.
If you a____ a little salt to the soup, it will taste more delicious.
Everyone can get on well with him, because he is easy to________(接近).
They are making a _______ (调查） of the population growth of the city.
While I was doing my homework, the ______(电） went off.
Water is a _______ (液体）without color or taste.
Children should be ____(独立的）in doing things and don't always rely on their parents.
I______(集中）your mind on study, and you'll make progress.
What is the ______(平均的）rainfall for summer in your country.
Nowadays many old people don't like living d______ ,for it is very noisy.