宾语从句中what where when 区别?

what 引导宾语从句,在其中可以充当主语,宾语等句子成分；where引导宾语从句,在其中充当状语,表地点.when 引导宾语从句,在其中充当状语,表时间.如： I don't know what I should do with the problem. He knew what s...