（ ） some mammals came to live in the sea is now known.

As a new graduate, he doesn’t know （ ） it takes to start a business here.

The tribe had been living in that part of the area for generations until the civil war ______.

It was in New Zealand _____ Elizabeth first met Mr. Morris.

All （ ） is to give him a warning.

The number of deaths from heart disease will be reduced greatly if people _____ to eat more fruit and vegetables.

He apologized _____ having to leave so early.

（ ） when she started complaining.

Dentists suggest brushing teeth at least twice a day to _____ them from decaying.

What time would it be convenient _____us to meet again?

It is a fact _____ most deaths from lung cancer are caused by smoking.

Our teachers always tell us to believe in （ ） we do and who we are if we want to succeed.