This is a common problem for millions of children around the world and not just at school, but also at home.

VOA: special.2009.12.21

This is a really interesting system because it also solves a problem for the cell.

这真的是一个有意思的系统,因为它也解决了细胞面对的难题

耶鲁公开课 - 生物医学工程探索课程节选

Then also a problem is you can't weigh things when you're eating out, so even if you were being incredibly precise about stuff at home and you were actually weighing things, you couldn't do that very well when you're eating out.

问题是,当你在外吃饭时无法称量食物,所以即使你在家中非常精确地测量食物,并且实际测量了每样物品,但在外吃饭时你可没法这样干

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

It's also an escape. A big problem we have in the neighborhood is obviously gangs,and family dynamics.

VOA: special.2010.11.04

It's - a suture or a stitch has to hold the wound closed so it has to have certain mechanical strength and imagine the problem of making something that's dissolvable so it disappears but also is strong enough to hold a wound closed reliably for a length of time.

能够拉紧切口的缝合线,就必须具有一定的机械张力,大家想像一下制造这种缝合线的难度,身体组织不仅要能吸收这种缝合线,而且这种线必须有足够的张力,一定时间内能够拉紧切口

耶鲁公开课 - 生物医学工程探索课程节选

Ensalaco says the recent arrests reinforce the reality that human trafficking is not just an international problem, but also a local one affecting every community in the United States.

VOA: standard.2009.11.13