根据括号内的汉语，完成句子。
1. The boy's family is a little poor. He can't ________ (买得起) a computer.
2. Sue is kind of heavy and she ________ (很少) plays sports.
3. They spent a whole day finishing the ________ (必要的) job.
4. We should make our hometown a more natural ________ (环境) to let more people come.
5. Her English teacher's words have ________ (激励) her a whole life.