______ his help, I would have missed the deadline.

• শূন্যস্থানে সঠিক উত্তর হবে - But for.
- Complete sentence: But for his help, I would have missed the deadline.

• But for someone/something
- English Meaning: without someone or something: except for someone or something.
- Bangla Meaning: ছাড়া, নইলে, না + অসমাপিকা ক্রিয়া।
- But for একটি phrase যার অর্থ - ​if it were not for বা ছাড়া/ব্যাতীত।
- এটি একটি past indicator তাই এরপর past tense বসে।
- The phrase "but for" is used to indicate an exception or a condition that changes the outcome of a situation.

• Example sentences:
- But for you, I would be completely alone in the world.
- The bookcases were empty but for a single dusty volume.

Source:
1. Cambridge Dictionary.
2. Accessible Dictionary by Bangla Academy.