a must的用法和樣例：
例句
- A raincoat is a must in the rainy season.
在雨季雨衣是必備之物。 - Our flat is such a long way from the office that a car is a must. There are no bus services at all!
我們的住房離辦公室有很長一段路，因而小汽車是必備的東西，那裡根本沒有公共汽車！ - His new novel is a must for all lovers of crime fiction.
他的新小說是罪案小說愛好者必須一讀的。
