题目内容：

根据所给句子和音标提示写出恰当的单词，每空一词（3分）

1.Please ____________ / nɒk / on the door before entering the teachers’ office.

2.Are you ____________ /fri:/ this afternoon? Let’s go swimming.

3.Sweet snacks give us ____________ /'enədʒɪ/ but they are not healthy food.