Do not insist ______ his going there.

Explanation: • শূন্যস্থানে সঠিক উত্তর হবে - on.
- Complete Sentence: Do not insist on his going there.

• Insist on/upon/ Insist on doing something
- To keep doing something, even if it annoys other people, or people think it is not good for you.
- বাংলায়,  কোনো কিছুতে জোর দেয়া বা পীড়াপীড়ি করা  ।
- Insist on/upon এর সাথে verb এর ing form বসে।

যেমন:
- He insisted on my going there.
- She insists on doing everything her own way.