Explanation

The idiom once in a blue moon means on rare occasions or rarely.

Explanation

During means کے دوران

The fire alarm rang during yesterday's meeting.

کل کی میٹنگ کے دوران فائر الارم بج گیا۔

Explanation

"Since" is used to indicate the time from a past event up to now or another point in the past.

The sentence refers to events that occurred after the speaker left school — so "since I left the school" is correct.

Explanation

I have never seen him after that unfortunate incident 

اس ناخوشگوار واقعے کے بعد میں نے اسے کبھی نہیں دیکھا

Explanation

"Some professors have signed a letter of protest and have sent it to the government."

کچھ پروفیسروں نے احتجاجی خط پر دستخط کر کے حکومت کو بھیجے ہیں۔

NOTE

First Mention: When an object (like "letter") is mentioned for the first time in a conversation or text, we generally use "a" to introduce it.

After this initial mention, if you refer to the same object again, you might use "the" because it’s now specific.

Explanation

Could is a modal verb.

Could can be used for polite/formal request

Could I have some more tea please? کیا میں مزید چائے پی سکتا ہوں؟

Explanation

Here was cheating shows past tense.

We use second form of verb (knew) in simple sentence of Past Indefinite Tense.

The examiner knew that the candidate was cheating 

Explanation

Frederick Winslow Taylor is the father of scientific management.

FW Taylor was an American mechanical engineer.

FW Taylor was one of the first management consultants.

In 1909, Taylor summed up his efficiency techniques in his book The Principles of Scientific Management.

Explanation

A case study is a research method that involves an in-depth and detailed analysis of a specific case or situation.

Explanation

The idea of an "open university" was presented in the Education Policy of 1972-80.