单词短语辨析 要原因Soon after we gathered in all the wheat crop,we be

单词短语辨析 要原因
Soon after we gathered in all the wheat crop,we began to ___it by using a machine.
A thrash B shield C shed D thresh (tell the differences between A and D)
The king ___over a great variety of peoples and lands for as long as forty years.
A reigned B governed (Why not )