As soon as he had hung up,he went over to the workmen and to

1 As soon as he had hung up,he went over - - - -是时间状语从句
2 - - - -and told them that if a -- - - -是宾语从句,that 是宾语从句的引导词,可以省略.
3 if a policeman ordered them to go away,they were not take him seriously.是条件主语从句.
（你很会挑选句子,因为一个句子里包含了三个从句,你的英语语感不错）