Question

1、when you arrived--- here,i was walking to the bus stop

2、-----wet it is!that is,----wet weather it is! 用how what填

Answer 1

1.第一句不填
解析：arrived 为不及物动词，后没有宾语，when为副词不能作宾语，所以不加介词，且here 是副词不用介词，如：go home，还有，there，when，where。
2.How wet it is!that is,What wet weather it is!
解析：这个是how，和what引导的感叹句，所选的特殊疑问词要以句子的被修饰部分决定。修饰形容词用how，如：How wet it is!被修饰部分为wet。修饰名词用what，What wet weather it is!被修饰为wet weather，wet是修饰weather作定语的，所以是名词weather，故用what。

Answer 2

第一句不填 here 是副词省略介词
2how wet是形容词用how修饰
what wet weather 名词用what 修饰

Answer 3

、How wet it is!that is,What wet weather it is!

Answer 4

1.就是arrived here 就可以了
2.How wet it is!that is,What wet weather it is!