This is an expensive ________ very useful book.

They are known that colds can be avoided by eating the right kind of food and taking exercise regularly.

They are planning on attending the convention next month, and so I am

AIDS can be transmitted by practicing unsafe sex and receive tainted blood from one who is already infected.

Two thousand years ago, most of Western Europe was populated by a fierce, strong, artistically people known as the Celts.

The average cat sleeps  sixteen hours for a day in short intervals called ‘cat naps'.

Although there are new drugs on the market, deaths from malaria are being increasing in some parts of the world.

There are differences and similarities between Vietnamese and American culture

It's raining, _______ I can't go to the beach.

After the police had tried unsuccessfully to determine to who the car belonged, they towed it into the station.

The geology professor showed us a sample about volcanic rock which dated back seven hundred years

I have gone to Copenhagen three times this year, I still want to spend my holiday there

Hardly he had entered the office when he realized that he had forgotten his wallet.

I'll offer it to Tom _______, he may not want it.

Thanks to a considerable number of material data, we know pretty much about ancient Egypt, but few historical records of Babylon are available.

Duke University in North Carolina has an outstanding collecting of documents concerning Southern history

You should know by now that I cannot stand it when my steak is not cooked properly as I always have mine well-made 

The lecture was _______ interesting and instructive.

The number of teaching assistants required meeting undergraduate course needs is rapidly increasing.

Since the Great Depression of the 1930’s, social programs such as Social Security have been built into the economy to help avert severity business declines.

Could you mind telling me the way to the nearest restaurant?