8A Unit4 知识点解析与练习1. What should I do? I dont know. = I dont know what I should do. (从句陈述句语序)= I dont know what to do. (特殊疑问词+to do)类似结构:如何做 _ 做什么 _ 什么时候离开 _ 去哪儿 _2. Here come a cat and two dogs. (全倒装:Here+谓语+主语) Here he is. (半倒装:Here+主语+谓语) 倒装句:动词单复看主语 没有现在进行时。Look! Here _ (come) the bus!3. instruction 指示;说明 可数 an instruction some instructions明确的指示_区分:tips for (doing) sth (做)某事的提示