Time is so valuable _____ So, we must be careful of spending time.

English is an international language. If you want to go abroad for higher studies,  you will have to learn English;

Drugs are very dangerous for our health. It is high time we  avoided drugs

You look a little bit tired. Would you mind  making a cup of coffee

There goes the proverb that  time and tide wait for none So never waste your time for nothing.

It was long since  we had met last So, I did not expect that he would recognize me at first glance.

I was not there at the moment. Had I been there,  you should fail in the exam