I think it is difficult.

我觉得它很难。

It is difficult to walk.

很难走路。

It is difficult but interesting.

它很难但很有趣。

It is difficult to warn people about them.

很难警告人们注意地震。

But for the students in one small village in China, it is difficult.

但对中国一个小村庄的学生来说，这很困难。

However, during the winter, it is difficult to attract the animals to cameras hidden in snowy forests.

然而，在冬季，很难吸引动物到隐藏在雪林中的相机前。

He needs to spend more time on his homework because it is difficult to become a professional sports star.

他需要花更多时间在作业上，因为成为职业体育明星很难。

It is difficult to drive when it is foggy.

当天气有雾时开车很困难。

It is difficult to make everyone happy.

让每个人都开心是很困难的。

It is difficult to concentrate in noise.

在噪音中集中注意力很难。