a complete and diverse line of

What happens to nitrogen in body tissues if a diver ascends too quickly？

A) It forms bubbles.

B) It goes directly to the brain.

C) It is reabsorbed by the lungs.

D) It has a narcotic effect.

A.diver

B.diversify

C.diverse

D.diversity

The trend of brain drain does the developing countries _______ degrees of harm.

A)diver

B)diversify

C)diverse

D)diversity

A.excellent impermeability

B.excellent resistance to weathering

C.good chemical stability

D.good stability in high temperature

1、There is one spot near the Philippines, where the sea is as deep as ().

A、13 kilometers

B、 9 kilometers

C、 2 kilometers

D、 11 kilometers

2、There are millions of tiny living things that float in the sea, and().

A、they live by eating fish

B、they live by eating plants

C、they are good food for many fish

D、they live by eating worms

3、Which of the following statements is true？ ()

A、When the diver dives under the sea, he gets colder and colder.

B、When the diver sinks to the bottom, he is to be colder and colder.

C、When the diver sinks in the sea, he will be rather cold.

D、When the diver dives downward, the sea gets colder and colder.

4、From the information given, why has the diver to wear a diving suit？ ()

A、Because the diver is likely to be attacked by fish.

B、 Because the water at great depths is very cold.

C、 Because the salt water seems unsuitable for diver.

D、 Because the pressure of water at great depths is immense (巨大的 ).

A.ship surveyor's report

B.a ship's certificate

C.a cargo inspection report

D.a diver survey report

Text 3

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a dive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper.

The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 30 meters in seawater a diver is exposed to a pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meters are present at five times their usual pressure. Nitrogen, which composes 80 per cent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen cause under these pressurized helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen in the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. The reverse occurs when the diver surfaces; the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism. To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during as- cent.

31. What does the passage mainly discuss？

A) The equipment divers use.

B) The effects of pressure on gases in the human body.

C) How to prepare for a deep dive.

D) The symptoms of nitrogen bubbles in the bloodstream.

In computing.a device driver (commonly referred to as simply a driver) is acomputer

program that operates or controls a particular type of device that is attached to a computer.A

diver provides (71) to hardware devices,enabling operating systems and other computer

programs to access hardware functions without needing to know precise details of the

hardware being used.

A.a software interface

B.a programming language

C.a function

D.an Internal Bus

A．The diver paused at the end of the board,gazing down at the smooth, greenish-bluewater meters below, his arms stretched out in front, his legs trembling slightly with anticipation and tension, drops of water falling from his fingertips into the swirling wind filled with murmurs from the crowd below and behind his solitary figur

E．

B．In opening minds, instilling values, and creating opportunities, education has no equal．

C．I have a dream that my four children will someday live in a nation where they will not be judged by the color of their skin but by the content of their character．