What caused the explosion in the factory it is still unknown

Archeological studies have provided evidence that the use of plants for decoration as well as for food developed early in the history.

I haven’t decided yet about either to buy a new car or second-hand one

Because there was no evidence against himself, Slade was released

It would be both noticed and appreciating if you could finish the work before you leave

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

Agronomists study crop disease, selective breeding, crop rotation, and climatic factors, as well soil content and erosion.

Neither of the two candidates who had applied for admission to the Industrial Engineering Department were eligible for admission.

One of the four underlined parts marked A, B, C, D in each sentence is not correct in standard English. Identify them: 

What you would do if you could speak French well? 

If the world's tropical forests continue to disappear at their present rate, many animal species ____________ extinct. 

The number of students attend the class dwindled until only two remained.

Choose the correct answer to complete the sentence. "Humans now have to suffer the effects of global warming ______ having treated the environment irresponsibly"

The number of time he spends gardening is increasing every day.

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

Since the Great Depression of the 1930’s, social programs such as Social Security have been built into the economy to help avert severity business declines

Choose the correct answer to complete the sentence. "Global warming has ______ impact on water supplies."

The world oceans have risen on average of 6 inches over the past 100 years, which has been considered as an evidence that global warming has an effect.

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

To be successful in an interview, you should control the feeling of pressure and making a good impression on the interview

Inventing by Roger Bacon, the magnifying glass led to the creation of other scientific tools which have produced immeasurable scientific progress.

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