a passing grade的用法和样例：
- I must admit that I never expect more than just a passing grade in his test.
- The instructor took the soft option and gave the boy a passing grade.
- His interest in photography is only a passing fad.
- Erhardt: Seaver, if this little demonstration of yours doesn't produce some quantifiable results, not only will you be barred from the field trip, you'll be lucky to get a passing grade in my class.
- A passing car splashed mud on my new trousers.
- A passing truck banged up the mailbox.