Question

he  has made two mistakes ______ the teacher has not deducted any
          marks. ( Supply a suitable Conjunction)                                     ​

Answer 1

Answer:

he has made two mistakes, but the teacher has not deducted any marks

For this question, you can use 'but' or 'yet'

Answer 2

Answer: he  has made two mistakes _but_____ the teacher has not deducted any marks.

Explanation:

HERE THE CONJUCTION IS BUT BECAUSE WE WRITE IT WHEN THERE IS SOMETHING WRONG / HAPPENING

MEANING OF BUT -  used to introduce a phrase or clause contrasting with what has already been mentioned

PLS MARK ME THE BRAINIEST IT TOOK TIME BUT HOPE IT HELPED