Not only the air but also the oceans ........... been polluted seriously. 

When the Panic of 1857, some us citizens who had been rich or comfortable became poor while few others, capitalizing economic shifts, became richer.

American pioneers did systems from logs with holes bored through their centers.

The term “metabolism” refers to the chemical changes which by iving things transform food into energy.

Pigeons, like many migratory birds, read positions of the Sun and stars in order to orient them

Mobility is one of the characteristics often demanded of executives, and they must accustom themselves to move as regularly.

Some studies show that young babies prefer the smell milk to those of other liquids.

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

If either of you take vacation now, we won’t be able to finish (this wor

The ancient Romans used vessels equipped with sails and banks oars to transporting their armies

The most substances expand in volume when they are heated

In the 1920s, Tulsa had a higher number of millionaire than any other U.S. city.

We must be very careful with sensitive issues such like this, to avoid give offence.

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

Interestingly, the United States both produces or uses more crude oil than any other national

As a young man, Darwin showed ittle promising as biologist.

Most bats roost in crevices, caves, or building by day and are active night or twilight

Working in the factory ........... not what children should do 

In spite modern medical technology, many diseases caused by viruses are still not curable

Mr. Anderson is responsible ________ hiring and firing employees. 

Though he did not develop sign language, Laurent Clerc brought on America from France