My teacher just gave us a task I really don't know how to do.

我的老师刚给了我们一个我真的不知道怎么做的任务。

Piqué : I really don't know.

皮克：我真的不知道。

I really don't know how to abreact .

我真不知道如何去发泄。

I really don't know about the streak.

我真的不知道情况。

I really don't know how to thanks you.

我真不知道该怎样感谢你。

I really don't know what to begin with.

我真不知道从什么(地方)开始。

I really don't know who is to apologise.

我的确不知道谁应该道歉。

I really don't know which argument is right.

我真的不知道争吵的哪一方是正确的。

Kay: I really don't know, but he wants to.

凯：我真的不知道，但他想去。

I really don't know, he replied anxiously.

“我真的不知道”，他不安地回答。