a superficial similarity的用法和样例：
- It is difficult to distinguish between the sexes in the field because external female genitalia have a superficial similarity to those of the male.
- I have only a superficial knowledge of the subject.
- I think that is a superficial view.
- A superficial injury is not serious.
- This is a superficial assessment to say the least.
- He has a superficial knowledge of this subject.