I have worked with children before ,so I know what_____in my

I have worked with children before ,so I know what_____in my I have worked with the children before,so I know what ______ I've worked with children before,so I know what___in my new I've worked with children before ,so I know what ___in my ne 英语语法真正高手请进have worked with children before , so I know what I've worked with children before ,so I know what to expect i I've worked with children before,so I know what _____ (expec I've worked with children before,so I know what to expect in I’ve work with children before, so I know what ___ in my job 选什么为什么呢、I‘ve worked with children before,so i konw what___in However,I know that I have to improve my English,so I've sta I won't believe you before I have seen it with my own eyes.这