於在

In a sentence

• 他所有的注意力都集中於在那本书上。

  All his attention is focused on that book.

  In this sentence, '於在' emphasizes the location or subject of focus, '集中於在那本书上', where the usage is somewhat redundant or stylistic.

• 於在北方，冬季的气候通常比较寒冷。

  In the north, the winter climate is usually colder.

  Here, '於在' indicates the location being described, '於在北方', demonstrating its use to specify a context.

• 我們於在大多数情况下，会选择更环保的方式旅行。

  We, in most cases, would choose more environmentally friendly ways to travel.

  In this instance, '於在' ('於' and '在' combined) is used to introduce the situational context, '於在大多数情况下', where it specifies the situation of the statement.