Several comet are discovered each year, but very few of them bright enough to be seen without aid of magnification

Because of its vast tracts of virtually northern forest, Canada has one of the lowest population density in the world.

Please don’t parking in those spaces that have signs reserving them for handicapped.

Like it or not, there is the rain and not car that will hold key to the future of domestic travel.

The most substances expand in volume when they are heated.

How many people _____ in the storm a few days ago? 

The bold way in which Margaret Mead defined the terms “family” – based as much on choice as on biological relationship – is possibly most enduring of her legacies.

Armstrong was the first person to set ________on the moon.

Southern California, is known for its mild winters, has become the new home for senior citizens escaping hard Northern winters.

Geologists find it useful to identification fossils inrock sample because certain assemblages of species are characteristic of specific geologic time periods.

One responsibility of human beings is not to interfere the actions of another people except in the face of injustice

Stephen Hopkins was  cultural (and political leadership in colonial Rhode Island.

Pictures of surface the planet Venus was received yesterday from the space probe “Explorer”, which was launched last year.

After George had returned to his house, he was reading book

What caused explosion in the factory it is still unknown

After working hard for so long, we decided to enjoy ourself to  nice long holiday

The capital of the United States, originally New York City, was moved Philadelphia where stayed until 1800.

Had we known traffic would be so bad, we did not drive back from work so early.

Mary and her sister just bought two new winters coats at clearance sale.

I _____ the film last night because I _____ it several times before.

Nobody was watching, so the little boy took the packet of sweets shelf and putting it in his pocket