It's a difficult one.

这是一个困难的问题。

youdao

The decision to search for birth parents is a difficult one to make.

作出寻找亲生父母的决定是困难的。

youdao

Curiosity, he argues, is the third key factor—and a difficult one to preserve.

他认为，好奇心是第三个关键因素，也是一个很难保持的因素。

youdao

And if one person dies, the other person may have a difficult time claiming the couple's money or property.

VOA: special.2011.05.23

It is a little bit difficult in the sense that to have gotten into Princeton, one almost certainly has had to know something about something. Right?

之所以比较困难是因为,一个人如果想要进入普林斯顿大学，他一定,对某个领域有一定了解？

普林斯顿公开课 - 人性课程节选

I want to illustrate one of the reasons why it has been so difficult to get a grasp on the hair cells in the inner ear.

我想用图例为大家说明一下,为什么难以捕获内耳中的毛细胞。

斯坦福公开课 - 7个颠覆你思想的演讲课程节选

Maybe some other bands should try and do the same, but it's a difficult one.

BBC: Rolling Stones: What is a fair price for a concert ticket?

The past year has been a difficult one, where our beliefs have been tested.

CNN: Powell: Americas dissatisfied with pace of reforms

His father says he knows that the transplant issue is a difficult one for families.

CNN: Boy not allowed to get life-saving transplant in Japan