It is the discovery of Cao Cao’s tomb, _____ was made in Anyang, Henan province, ____ has received widespread attention．

______ some problems have arisen in the process, we are confident that we can handle them.

 There is no doubt ______ they did a completely bad job at that very moment.

 Go and get your coat. It’s ________ you left it.

 When he was a little boy，he ______ on the farm.