If you don’t try your best to learn all subjects, you will ___ behind.

I was       in the middle of my call because I had no more pennies to put in the box.

He started to study ecology and decided to  _______his whole life to the science.

 The police are to ______ the traffic accident that we don’t know _____.

—Did anyone support you at the meeting?—Moore was the only person who __________ my opinion.