Parents are taught to be aware of _____ important mental health is to their children.

I suppose that when I come back in twoyear’s time all these old houses will ____ down．

Mr. Green put up his tent right now as soon as he arrived on the island.

He transplanted the little tree to the garden ____ it was the best time for it.

_____ we celebrate a festival it changes a little and in that way we keep our culture alive．