This was of great concern because the number of polio cases shouldn't go up as the vaccine is being even more actively distributed through the country, so what happened?

这个现象让人担心,因为小儿麻痹症的发生数量,不应该在疫苗全国范围内普及后,反而有所上升,那么到底发生了什么

耶鲁公开课 - 生物医学工程探索课程节选

I'm concern about our safety "Maybe we should go some place else."

我觉得这儿不安全，“要不然换个地方吧。”

Let's 课堂 - SpeakingMax英语口语达人

's stock to investor frustration about a scandal that refuses to go away and concern over the BSkyB deal.

WSJ: Phone-Hacking Scandal Builds Momentum in U.K.

The irony is that Democrats have found, in Mr. Waxman, an even more extreme antibusiness tribune, who will no doubt use his new powers to go after any concern that turns a profit but refuses to pay his party the obeisance of campaign cash and regulatory submission.

WSJ: The Waxman Democrats

If your son has repeated episodes of reporting a voice or having other strange experiences, my level of concern would go way up.

CNN: Is my 10-year-old hearing voices serious?