对两名失踪青少年安全的担忧正在增加。

___Concern for the safety of the two missing teenagers is growing.

公众对最近在食物中发现的有毒物质有很多担忧。

There's a lot of public ___concern about dangerous toxins recently found in food.

我的担忧是你没有完成足够的工作。

My ___concern is that you're not getting enough work done.