第一，迷你对话

A: I won't select computer science this semester.

这学期我不想选修计算机课了。

B: Why not?

为什么不选呢？

A: It seems to be out of my depth.

对于我，太难了。

第二，地道表达

be out of one's depth

1. 解词释义

Be out of one's depth的意思是“超出某人的理解能力或力所不及”。

2. 拓展范例

E.g. When they start talking about economics, I'm out of my depth.

他们一谈起经济学，我就一窍不通了。

E.g. The student was out of his depth in discussion on the Middle Ages.

那个学生对关于中世纪的讨论感到难于理解。

E.g. I'm out of my depth when it comes nuclear physics.

我对原子核物理学一窍不通。

E.g. He's quite out of his depth, you must take him on as your apprentice.

他相当外行，你就收他做徒弟吧。