Explanation

Injurious to means مضر صحت یا نقصاندہ

We generally use to after detrimental and injurious.

To is a preposition here.

Smoking is injurious to health means تمباکوشی مضر صحت ہے

Explanation

• The preposition "with" is used to express satisfaction or dissatisfaction about something or someone. 
  
• So the sentence would be: "I am satisfied with his performance."
• میں اس کی کارکردگی سے مطمئن ہوں۔

Explanation

We generally use by with time.

by is a preposition here

What is the time by your watch means آپ کی گھڑی میں کیا وقت ہوا ہے

Explanation

• A fool dog fell into the water.
• ایک بیوقوف کتا پانی میں گر گیا۔
• The dog fell within the water, so we use the "into" preposition.
• The "into" preposition is used in a sentence because they show the dog is within or inside the water.
• Into is a preposition that shows what something is within or inside.

Explanation

The correct sentence should be: "Send this letter to my address."

یہ خط میرے پتے پر بھیج دو۔

The preposition "to" is used to indicate the recipient or destination of the letter.

Explanation

Superior, Senior, Junior etc are followed by preposition To.

He is superior to me.

She is senior to me.

Explanation

Explanation

"She is senior to me." 

This phrase correctly uses "to" to compare seniority or rank between individuals.

Explanation

Generally preposition "of" is used after "proud".

Proud itself is an adjective.

Explanation

She assured me of her help.

اس نے مجھے اپنی مدد کا یقین دلایا۔

Here "of" shows that the "help" belongs to "she" (noun).