The first vaccine ever developed was used to combat and fight a smallpox, a disease resulting infection by a virus

Commercial letters of credit are often used to financing export trade, but they can other uses.

The student realized with disappointment that he had learned new nothing in lecture.

The team leader demanded from his team members a serious attitude towards work, team spirit, and that they work hard 

The top of mountain covered with snow during winter

Once the scientist had figured out the precise path the comet, he is finding that he was able to predict next appearanc

Since firework are dangerous, many countries have law preventing business to sell them

Conservation organizations help erfor to preserve the ecology of an area by keeping of endangered species

The journalist has not finished the article on negotiation already

Although usual living on or under rocks or on coral reefs, marine snails have been observed in great various of habitats

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

Forgetting something usually mean an inability to retrieve the material that is stored somewhere in the memory.

Three weeks …………not enough for the holiday. 

One of the countries I would like to visit ……….Italy

The native people of the Americans are called Indians because when Columbus landed in the Bahamas in 1492, he thought that he has reached Eastern Indies

The most of the energy used in our homes and factories generated from coal, oil and natural gas.

Choose the best option:

Thank you very muck for your gift on my birthday.

Isle Royal National Park in Lake Superior can only be reached by the boat.

Not one (one hundred children exposed to the disease are ikely to develop symptoms of it.

Frank Wright has been acclaimed by colleagues as the greater all modern architects

It was after shortly microscopes were introduced at the beginning of seventeenth century micro organisms were actually sighted.