A light year is the distance that light travels in one year calculated by using the speed of 186,284 miles the second as a base

Had I known the carpenter was going to take three days to show up, I ___________ the materials and done the work myself. It would be finished by now. 

The wooden fence surrounded the factory is beginning to fall down because of the rain.

It was near end of prehistoric times that the first wheeled vehicles appeared.

Mr Ross, our old history teacher ruled his classes by a rod of iron!

Many heavy work that was once done by hand can now be done more easily with the help of compressed air.

Because it is a healthy way to exercise, aerobic dancing is considered as an excellent method for release tension.

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

Believed that Jack had got home safely, we felt relieved.

I miss my old motorbike, I wish I ____ it. I had it for years. 

The skin receives nearly the third of the blood pumped out by the heart.

Humus is formed during soil microorganisms decompose animal and plant material into usable elements by plants 

The bath overflowed and the water dropped through into the living room

Choose the correct answer to complete the sentence. "Having seen people suffer global warming consequences, people decided________ carbon footprints."

Bats use echoes of their own high – frequency sounds to detect food and avoiding obstacles.

Long prized for its medicine value, ginseng these days has become the most common of energy-boosting drinks particularly for high- performance athletes.

Electric motors range in size from the tiny mechanisms that operate sewing machine to the great engines in heavy locomotives.

Choose the correct answer to complete the sentence. "Global warming occurs ______ the greenhouse gases in the atmosphere trapthe heat from the sun."

Choose the correct answer to complete the sentence. "In the first case, the dried material is scraped off the roller as a thin film _____ is then broken up into small, though still relatively coarse flakes."

A smile can be observed, described, and reliably identify; it can also be elicited and manipulated under experimental conditions

The teacher decided to fail the student with the grounds of his poor performance in tests and too small progress