The substance is very toxic. Protective clothing must be worn at all times.

A. Since the substance is very toxic, so protective clothing must be worn at all times.

B. So toxic is the substance that protective clothing must be worn at all times.

C. The substance is such toxic that protective clothing must be worn at all times.

D. The substance is too toxic to wear protective clothing at all times.

The government knows the extent of the problem. The government needs to take action soon.

A. The government knows the extent of the problem whereas it needs to take action soon.

B. The government knows the extent of the problem so that it needs to take action soon.

C. Knowing the extent of the problem, the government needs to take action soon.

D. The government knows the extent of the problem, or else it needs to take action soon.

People believed that Jane retired because of her poor health.

A. Jane is believed to have retired because of her poor health.

B. Jane was believed to have retired because of her poor health.

C. It is believed that Jane retired because of her poor health.

D. Jane retired because of her poor health was believed.

"I have never been to Russia. I think I shall go there next year.” said Bill.

A. Bill said that he had never been to Russia and he thought he would go there the next year.

B. Bill said that he would have never been to Russia and he thinks he would go there the next year.

C. Bill said that he had never been to Russia and he thinks he will go there the next year.

D. Bill said that he has never been to Russia and he thinks he would go there the next year.

Not one in one hundred children exposed to the disease are likely to develop symptoms of it.

(A) Not one

(B) Are

(C) Symptoms

4.  It

Đáp án:

_________ the room, the man was no longer there.

A. Entering B. When we entered C. On entering D. Having entered

The notion that students are not sufficiently involved in their education is one reason for the recently surge of support for undergraduate research

(A) Notion

(B) Are not

(C) Their education

(D) Recently

 _________ anxious to please us, they told us all we wanted to know.

A. Be B. To be C. Being D. In being

_________at by everyone, he was disappointed.

A. Laughed B. Laugh C. Laughing D. In laugh

The eastern bluebird is considered the most attractive bird native of North America by many bird-watchers.

(A) Bluebird

(B) Considered

(C) Native of

(D) By