I have passed all the tests with flying colors

SUMMER vacation is over, so wake up, boys and girls! Time to hit the books. How about your marks last semester?

A: What was your score in math?

B: My grade was a C+. C+

Note: We can use "grade", "mark" and "score" for the result of a test. When school work is given an A, B, C or D, we can use "grade" or "mark". "C+" is pronounced "C plus". And "C-" is pronounced "C minus".

A: How'd you do in English last semester?

B: I earned 95 out of 100 points. 95100

Note: If school work is figured on a numerical system, we use score instead of grade. In China, a perfect score is usually 100 points. But in some Western countries, a perfect score could be, for instance, 25 or 250. So you'd better add, for instance, "out of 100 points", as we did here.

My score on the spelling test was 78. 我的拼写测验考了78分。

Note: We use the preposition "on" here. Or we can simply say "I got a 78 on the spelling test." (Don't forget the "a" here.)

I passed the final exam! That's amazing! I thought I'd flunked it! 我期末考试及格了。太神奇了！我还以为我会挂科呢！

Note: We say "fail" or "flunk" if we don't pass a test. "Fail" is more formal, "flunk" is colloquial (口语的).

A: Did you pass the mid-term?

B: I passed it with flying colors.

Note: "With flying colors" means "easily and successfully". If you only earned 60 out of 100 points, you may have to answer "I did OK on the test" (我考得还行), or "At least I didn't fail." (至少我没不及格)

The exams are finally over. Now the teachers are busy grading them. 考试终于结束了，现在老师都在忙着判卷子。

Note: Or you can say "marking [the exams]" or "scoring [the exams]".