根据句意和所给的首字母提示，补全句子中的单词。
1. If there were more trees on the earth, there would be l____ pollution.
2. I don't like eating lemon. It t____ too sour.
3. The injured people were taken to hospital i____ after the accident.
4. Look, the expression on his face s____ that something bad must have happened to him.
5. According to an ancient Chinese legend, the emperor Shen Nong d____ tea.