题目内容

11.                The managerthe workers how to improve the program since 9 a.m. (tell)

经理自从9点起就一直在告诉工人们如何完善这个项目。

11. has been telling考查现在完成进行时的用法。时间状语"since 9 a.m."暗示时态应为现在完成时；"一直在告诉"暗示时态应为进行时，因此结合起来本句时态应为现在完成进行时。现在完成进行时的用法主要有两种：(1)表示动作从过去某时开始，一直延续到现在，而且现在还在进行；(2)表示一个近期内时断时续、重复发生的动作。其构成为have / has been doing sth. 

练习册系列答案
相关题目

(   ) 8. Cats and dogs have quite different natures  dogs like company，while cats are      

A. independent    B. gentle C. conscious    D. stubborn

(   ) 5. He decided to travel to Hawaii with his family，so he reflised our           to Europe.

A. addition    B. consideration C. conclusion    D. invitation

Pretoria, South Africa. Hundreds of swimmers are playing in the water along a South African beach. Suddenly a huge shark appears offshore and heads for the bathers. Before it can get close to the swimmers, the shark, for some mysterious reason, starts swimming parallel to the beach. Then it turns away from the shore and heads out to sea,leaving the swimmers untouched.

Such a scene will soon become common along shark infested(鲨鱼出没)shores. An electrical engineer from the University of Pretoria has developed an electrical system that repels(击退)sharks by controlling their movements. Confixsed by this action, the sharks end up turning away from the beach.

In this unusual shark repellent method, an insulated(绝缘的)cable is buried on the bottom of the sea around a beach from which people swim. When an electric current is sent through the cable， an electric field is produced in the water above the cable.

When the shark swims into the electric field, nerve cells just below the shark's skin detect the field. The electricity produces a reflex(反射)action in the shark's muscles, causing the dangerous animal with sharp teeth to swim parallel to the cable. Confused by increasing loss of control of its muscles, the shark suddenly changes its direction and heads seaward, away from the electric field.

In a test of the invisible new shark-repellent system，a cable was placed around a beach in St. Lucia,an island in the tropics. A protective net,which had been installed around the beach a long

 

time ago to keep sharks from swimmers, was left in place during the experiment.

When the electric field was left on for more than a year and a half,no sharks were found in the nets. However, when the power was turned off, 89 sharks ended up in the nets.

of many sharks，say biologists. Currently，thousands of sharks die each year when they become trapped in protective nets that surround holiday resorts in Africa and Australia. About 10 to 15 humans are killed by sharks annually.

(   ) 4. In the first passage, why doesn't the shark attack the swimmers?

A.   Because there are many swimmers in the water.

B.   Because the shark doesn't want to eat the swimmers.

C.   Because of some mysterious reason from the God.

D.   Because there is an invisible electric field confusing the shark.

(   ) 5. An electrical engineer from the University of Pretoria has developed                   -

A. a protective net    B. a new shark-repellent system

C. the electric field    D. an insulated cable

(   ) 6. An electric field is produced in the water above the cable       

A.   only when the shark swims into the electric field

B.   only when an insulated cable is buried on the bottom of the sea around a beach from which people swim

C.   only when an electric current is sent through the cable

D.   only when the sharks are trapped in protective nets

(   ) 7. Which of the following is NOT true according to the passage?

A.  Protective nets had been installed around the beach earlier than the new shark re?pellent system.

B.  This new kind of shark repellent system will take place of the protective nets.

C.  Thousands of sharks die and about 10 to 15 humans are killed by sharks each year in Africa and Australia since this new system was put into use.

D.  Using the electric wall method instead of nets to protect bathers would avoid the needless death of many sharks.

6. The news        has caused many people to sell their houses at lower prices. (fall) 

房价将要下跌的消息已经造成很多人低价卖房。

16. Tm afraid you'd better not call me at 3 o'clock on the afternoon tomorrow. I            then. (have)

你最好不要在明天下午3点钟给我打电话。那时我在开会。

23. Never in my life        such a fascinating scene. (enjoy)

我一生中从未欣赏过这么迷人的风景。

(   ) 10. The building dating back to 1883 was named Ford Hall        a man named James

Ford.

A. in place of    B. in celebration of C. in memory of    D. in favor of

(   ) 6. Born into a family with three brothers, David was      to value the sense of sharing.

A. turned down    B. held back C. referred to    D. brought up

违法和不良信息举报电话：027-86699610 举报邮箱：58377363@163.com

精英家教网