这个孩子正在专注地玩积木。

The child is ___concentrating on playing with building blocks.

这种浓缩果汁需要加水稀释后才能饮用。

This ___concentrated juice needs to be diluted with water before drinking.

学生们把注意力集中在即将到来的考试上。

The students ___concentrated their attention on the upcoming exam.