21.引起讀者興趣
What if the evening disappeared from the world?
如果黑夜從世界上消失了，那會怎么樣呢？
What if you got hit by a truck while crossing the street?
如果你在過街時被車撞到，怎么辦？
What if everyone jumped a cliff? Would you do it either?
要是別人都去跳崖，你也會去嗎？
Suppose that there was no purified water, what would we drink?
假如沒有純凈的水，人們喝什么？
Suppose that there was an earthquake, what would be the right way to escape？
如果發生地震，正確的逃生方法是什么？
Suppose that we missed the train, what shall we do?
如果我們誤了火車，我們該怎么辦？