why not後面加什麼詞性

例句：

Why not go out and see if there's some place we can dance?

為什麼不出去看看是否有我們可以跳舞的地方？

Why not retrain for a job which will make you happier?

為什麼不接受新的培訓，找一份讓你更快樂的工作？

Why not have it out with your critic, discuss the whole thing face to face?

為什麼不和批評你的人講個明白，面對面地把整件事情談一談呢？

Why not stop them (from) polluting the river?

為什麼不阻止他們污染這條河呢？