Vocabulary and Grammar

Organisms play ________ important role in keeping the nature balanced.

A big ocean in the world is divided ___________ five different parts: the Pacific, Atlantic, Indian, Antarctic and Arctic Oceans.

Today’s scientists have overcome many of the challenges of the depth by ________ more sophisticated tools.

We wish _______ to college next year. 

Is submarine a ___________ of transport in your country?

I _________ smoking should be banned, especially in restaurants.

They can send submarines to take photographs of animal life and bring back to the __________ for further study.