On Oct. 12, 1989, some Chinese scientists were working at the computers to look for the in- formation they needed. Suddenly they saw a lot of very bright spots crossing the computer’s screens. At the same moment the computers were working much slower. To find out what was happening, they stopped their work to check some parts of the computers. To their horror, they found out that most of their stored information was got rid of by computer viruses (病毒). All these computers had been infected by computer viruses.
It is said that the computer viruses were made by a group of young men fond of playing tricks. They all have excellent education. They created the viruses just to show their intelligence. These kinds of computer viruses are named Jerusalem Viruses. These viruses can stay in computers for a long time. When the time comes they will attack the computers by lowering the functions, damaging normal programs or even getting rid of all the information.
A. play tricks on operators of the computers
B. frighten the scientists
C. damage all the computers
D. attack Jerusalem
On Oct. 12, 1989, some Chinese scientists were working at the computers to look for the in- formation they needed. Suddenly they saw a lot of very bright spots crossing the computer’s screens. At the same moment the computers were working much slower. To find out what was happening, they stopped their work to check some parts of the computers. To their horror, they found out that most of their stored information was got rid of by computer viruses (病毒). All these computers had been infected by computer viruses.
It is said that the computer viruses were made by a group of young men fond of playing tricks. They all have excellent education. They created the viruses just to show their intelligence. These kinds of computer viruses are named Jerusalem Viruses. These viruses can stay in computers for a long time. When the time comes they will attack the computers by lowering the functions, damaging normal programs or even getting rid of all the information.
A. damage
B. spread
C. lower
D. attack
Within 80 years, some scientists estimate, the world must produce more than eight times the present world food supply. The productiveness of the sea raises our hopes for an adequate food supply in the future. Aided by men of science, we have set forth to find out that 70 percent of the earth remains unexplored the ocean depths. Thus, we may better discover and utilize the sea’s natural products for the world’s hungry.
It is fish protein concentrate that is sought from the seas. By utilizing the unharvested fish in United States waters alone, enough fish protein concentrate can, be obtained to provide supplemental animal protein for more than one billion people for one year at the cost of less than half a cent per day per person. The malnutrition of children is terribly tragic. But the crime lies in society’s unrestrained breeding, not in its negligence in producing fish powder. But wherever the population projects are carefully considered, the answer to
A. the oceans will help to provide enough food for the world in the future.
B. thirty million tons of food products are taken from the sea every year.
C. city sewers are pouring forth polluted matter into bays and coastal waters.
D. a steady increase in population will result in more hungry mouths to feed.
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