Explanation

• He is fortunate in getting the First Prize وہ پہلا انعام حاصل کرنے میں خوش قسمت ہے۔
• Usually fortunate is followed by In.
• In is a preposition here. 

Explanation

Use of At and In (For places)

At is used for small places. (villages, cities and towns)

In is used for large places and big cities, countries etc.

For example: He lives in Karachi. We stayed in Lahore for three days.

Explanation

On refers a surface.

On means اوپر

On is a preposition here.

What is that on the ceiling وہ سیلنگ پر کیا ہے

Explanation

Generally prompt is followed by In.

Prompt means بغیر کسی دیر کے

He is prompt in payment. 

Explanation

We use since from a particular time in the past until a later time, or until now.

Explanation

"I don't really want to go, besides, it's too late now."

"Besides" is used to add extra information, meaning "moreover" or "in addition to that."

It modifies the whole sentence, which is a function of an adverb.

Why not the other options?

Preposition  (e.g., "Besides my brother, no one was there." – Here, "besides" functions as a preposition.)

Conjunction (It does not join two clauses like "and" or "but.")

Noun ("Besides" is not a thing or entity.)

Explanation

Surprise is a verb which means حیران رہ جانا

We use at after surprise.

At is a preposition here. 

All of them are surprised at his rudeness ہم سب آپ کی بدتمیزی پر حیران ہیں

Explanation

We use by when we talk about “means of transport”.

We travel by bus.

“On” is used with a specific bicycle, bus train, ship plane.

Come on my bicycle.

Explanation

Fascinated by means attracted by.

By is a preposition here.

Fascinated means گرویدہ ہونا

The children were fascinated by all the toys in the shop windows.            

Explanation

Generally fight is either followed by with or against.

With or against are Prepositions here.

Fight with your enemies اپنے دشمنوں سے لڑو