We cannot buy food and clothes and pay for rent and utilities on $20 a week.

我们无法靠每星期$20来购买食品、衣物，付房租和水电费。

《柯林斯英汉双解大词典》

For example, the two brothers have to go to the school library to borrow books for their scientific projects, and Mr. and Mrs. Smith need to go out shopping because they cannot buy things online.

例如，两兄弟必须去学校图书馆为科研项目借书，史密斯先生和夫人需要出去购物，因为他们不能在网上买东西。

youdao

Sex-appeal is a commodity one cannot buy.

性感是买不到的商品。

youdao

In the future, project organizers want to have international donors buy the kits for girls and young women who cannot afford them.

VOA: special.2009.03.16

So Kurt Russell and his friends attend a small private college, which cannot afford to buy a computer.

所以Kurt，Russell和他的朋友,参加了一个小的私立学院，那里买不起一台电脑。

哈佛公开课 - 计算机科学课程节选

should Russia buy in the West because its own industry cannot do it, or should the country somehow try to manage on its own?

VOA: standard.2009.03.20

For billionaires who cannot buy good press, there is the option of buying the press.

NEWYORKER: The Miner��s Daughter

Some types of spending are already banned: for example, parties cannot buy television advertising.

ECONOMIST: Fuelling the political machine

Does it matter if people cannot buy and sell homes as frequently as before?

BBC: When will the long slump in house sales end?