谢谢奉国平网友提醒！Swan的第4版关于enough在第450节和171节这两个地方，分开讨论了！谈谈这一类的enough的问题。一开始我看到网友这个问题就觉得跟我看到的具体实例不符合，原来是Swan的一个说法，遗憾的是Swan简单描述了一下，就没往细里说，导致我们的理解出现偏差。大彭老师说“enough做表语时(Swan说的without a noun，单独用)，其主语通常应该是表示数量或隐含有数量意义”，这种说法当然是靠谱的，但除此之外，如果是语境比较清楚的情况下，也是没问题的：

1. This food is enough for our needs. (Longman lexicon of contemporary English1981)

2. That noise is enough to waken the dead! （Longman Lexicon of Contemporary English1981）

3. “There are enough people talking about the bad things in that part of the world. It’s time for some good. The food is enough.” I surprise myself with the forcefulness of my answer.（2015）

4. The stuffed parrots and Nicaraguan knickknacks add an air of festivity, but the food is enough to get the party started.

5. An INGO has a truck with perishable food in a region where starvation is widespread. The food is enough to protect up to 800 people from premature death.

6. We gained the support we needed to keep us on track. We love our new healthy eating plan. The food is enough to satisfy the whole family, including our two teenage children.

7. When the two orders came, the two gentlemen felt ashamed of themselves. The meat was enough for four or five people.

8. We Esquimaux think only of our stores of food; shall we have enough meat for the long winter or not? If the meat is enough, we have no need to think about anything else.

9. Earl’s father eked out a living by chopping wood during the day and hunting at night. In those days, the cured animal hides brought in ten cents apiece and the meat was enough to fill his children’s stomachs.

10. If properly stored and distributed using the appropriate technology, the meat is enough to feed 300,000 starving people year round.

11. A recipe in a cookery book will tell us that the dish is enough for four persons, and a notice in a bus will announce that only six persons are allowed to stand when all the seats are full. （Wood博士）

12. That noise is enough to drive me demented! （Chambers Universal Learners Dictionary1980）

13. The sight is enough to break your heart. (Concise Oxford American Dictionary(2006))

14. The price of these tickets is enough to make anyone gag. (Longman Advanced American Dictionary第3版)

15. Living with my parents is enough to screw anybody up.((Longman Advanced American Dictionary第3版))

16. The music industry, with its inside deals and wheels within wheels, is enough to confuse the toughest business minds. (Longman American idioms dictionary1999)

17. The smell of his cooking is enough to stink us all out!(Longman dictionary of contemporary English1984)

18. This lousy weather is enough to put anyone off camping.(Longman dictionary of contemporary English第3版)

19. At my age, the walk into town is enough to invigorate me.(Longman dictionary of contemporary English第5版)

20. The money that I earn is enough to meet our basic needs.（Oxford American dictionary for learners of English2011）

21. The money is enough for food and little else. The family has meat one day a week, and soup, beans and potatoes the rest of the week.

22. The look on his face is enough to set you off！（Oxford Dictionary of Current Idiomatic English I Verbs With Prepositions and Particles）

23. That assignment is enough to make me lose my reason.（The American Heritage Dictionary of Idioms2013）

24. The mess in his office is enough to turn your stomach, but in fact he works very well.（朗文英汉双解英语成语辞典）

25. The noise is enough to drive one mad.（现代英语用法词典修订版张道真）

26. The traffic problem is enough to give a policeman gray hairs.（英语习语大词典武汉大学出版）

27. The noise of his motorbike is enough to wake the dead.（英语习语大词典武汉大学出版）

28. The story of his sufferings is enough to make your blood run cold.（英语搭配大辞典小日本）

29. The monotony of prison life is enough to drive anyone insane.（Longman Language Activator第2版）

有些实例并没有完整列出上下文，篇幅影响。

enough 作表语时，其主语通常应该是表示数量或隐含有数量意义。如：

Five minutes is enough. 五分钟就够了。

A day or tzoo is enough. 一两天就够了。

Four copies is enough. 四册就够了。

Eight hours of sleep is enough. 八小时睡眠足够了。

One glimpse at himself in the mirror was enough. 让他照着镜子瞧上自己一眼就够了。

I met him only the once, and that was enough. 我就见过他那一次，那就让我受够了。

She did it just the once, and once was enough. 她只做了这一次，而一次也就够了。

I must double the amount, or it won’t be enough. 我必须把数量增加一倍，不然会不够。

而网友的句子中 the food 并非表示数量或隐含有数量意味，所以不是很合适。但如果改成下面这样的句子，则完全可以：

Two kilos of food is enough.

Two baskets of food is enough.

Three bags of food will be enogh.

My food together with his food should be enough.