根据内容提示完成句子（每题1分，共5分）
1. （这里一定有什么误会）. I don’t know what you’re talking about.
2. This character was a little failure but was loved for his optimism and (战胜一切困难的决心).
3. The teacher told us to (将难懂的单词划线) and look them up in the dictionary.
4. Nobody before Jane fully understood chimp behaviour. She spent years (观察并记录) their daily activities.
5.The function of the smile is to show happiness and (使人放松).