I happened to know about him from the ______(visitor) book.正

I happened to know about him from the ______(visitor) book.正 I want to know _____ about him I want to know what --------- him.A .happened B,has happened I know nothing about the young lady ______ she is from Beiji what happened to him at last __more than i know.A.were B.to 同义句转换：We required all the visitor not to throw waste about i ( ) the visitor from I didn’t know what had happened to him 有语法错误吗 Do you know __________? A.what happened to him? B.what the m I'd like to ______ the book. 英语语法高手请进1.I happened to _____the news on TV.A.know about B.l ______ the book,I learned a lot about animals.介词