When I came in,I found_____.

When I came in ,I found _______. they___the maths problem when i came in They____the maths problem when I came in. i _____cards when the teacher came in . 关于when的用法1.When i came in,i ____(call) them up.2.When i came The dog_________(lie) on the floor when I came in The girl ____ (read) a book when i came in. I stopping playing games when my mother came in. The blackboard ________ (clean) when I came in. I came in when she was reading 为什么错了? ___________(be)you________(read)books when i came in What ____ you ____(do) when I came in?