It is high time we (change ) our food habit . Here the correct form of verb is –

1. changed
2. have changed
3. should have changed
4. should change

Answer: changed

Explanation: It is high time থাকলে আর এর পর sub আসলে sub – এর পর verb – এর past form ব্যবহৃত হয়। সুতরাং change – এর past form changed শূন্যস্থানে বসবে ।