A calorie is the quantity of heat required to rise one gallon of water one degree centigrade at one atmospheric pressure.

Because the diamond is the hardest naturally occurring substance, it is used in industry for to cut, grinding, and boring other hard materials.

A dancing is the oldest and liveliest of the arts.

Drug abuse have become one of America’s the most serious social problems .

Being a nurse involves being cheerful, working unsocial hours, and come home with me smelling of disinfectant.

Many people have stopped to smoke because they are afraid that it may be harmful to their health.

Some bacteria are extremely harmful, but anothers are regularly used in producing cheeses, crackers, and many other foods.

Mosquitoes are such fast breeders that it is almost impossible to control them either by draining areas where they breed or to spary them with pesticides

The students in the dormitories were forbidden from going out after 11:30 p.m., unless they have special passes.

The composer Verdi has written the opera Aida to celebrate the opening of the Suez Canal, but the opera was not performed until 1871 

There is a local elected council which has responsibility for roads street lighting and other facilities

Many birds will, in the normal course of their migrations, flying more than three thousand miles to reach their winter homes.

If I ____ the flu, I would have joined you for the trip. 

The purpose of traveler’s checks is to protect travelers from theft and accidental lost of money.

Muscles are essentially made up by elastic fibers that lend flexibility to the body

Jill regrets having bought that second-hand laptop. She wishes she ______. 

Salt was once too scarce and precious that it was used as money.

 Scientists sent ............ expedition to ............ Mars during .......... 1990s. 

Urban consumers have formed co-operatives to provide themselves with necessities such groceries, Household appliances, and gasoline at a lower cost.

The intent of the Historical Society is to restore old buildings and the increase of interest in the history of the area.

We call her as ‘Auntie Flo’, though she is not really in any relation to us