Mobile phone use among children has become a problem.

孩子们使用手机已经成为一个问题。

youdao

Mobile phone used among school kids has become a problem for the school years, so one of the rules in our country says that school kids are not allowed to bring mobile phones to school.

小学生在学校使用手机已经成为一个问题，因此我国有一项规定是，小学生不能把手机带到学校。

youdao

How it become a problem?

怎么就变成问题了呢？

youdao

He says many don't even have the active ingredients in them. There is a tendency to treat all fevers as malaria in West Africa,and resistance to otherwise effective treatments, like cloroquine, has become a problem.

VOA: standard.2009.04.25

Now this will become a problem obviously when we talk about Judaism, because Jews--the Greek rulers, were trying to do the same thing with Jewish gods and Jewish figures, as they had elsewhere.

显然，这种方法用在犹太教会产生问题，因为犹太人。。。希腊统治者试图用，同样的方法，处理犹太神。

耶鲁公开课 - 新约课程节选

Okay, it could be a bit of a problem if this text has become the basis for a system of religious faith or belief, and your assumptions about it are that its telling a truth that is singular in nature.

如果这本书成为一些宗教信念系统的基本,那就有问题了,你会臆断，这本书上的都是真确的，都是非凡的。

耶鲁公开课 - 旧约导论课程节选

Lest you think that this will not become a problem in the United States, think again.

CENTERFORSECURITYPOLICY: Louisiana at leading edge in fight against Shariah

The operation will focus on the south of the county, where deer poaching has become a problem.

BBC: Operation targets wildlife crime in Cumbria

Thus the crucial issue isn't merely the level of debt, though at some point that can become a problem.

WSJ: Review & Outlook: Debt and Growth