It is ten years since he ________ the country.

• 1) Any Present tense + since (সময় বুঝাতে) + Past Indefinite
Example:
- It is ten years since he left the country.
- Many years have passed since his best friend died.

2) Past tense + since + Past Perfect
Example:
- It was ten years since his best friend had died.

• যেহেতু প্রশ্নে উল্লেখিত বাক্যে since এর পূর্বের clause টি Present tense এ আছে, তাই এর পরের cluse এ verb টি Past Indefinite এ হবে।