In today's world, insurance plays a vital role in the economic and social welfare of the entire population. The wish to guard against dangers to life and property is basic to human nature. By using va
Plastics are materials which are softened by heat and set into lasting form when shaped in a mold. Some are natural; some are semi-synthetic(半合成的) , the result of chemical action on natural su
Homing pigeons are placed in a training program from about the time they are twenty-eight days of age. They are taught to enter the cage through a trap and to exercise above and around the loft(鸽棚
The difference between a liquid and a gas is obvious under the conditions of temperature and pressure commonly found at the surface of the Earth. A liquid can be kept in an open container and fill it
Scientists at Sussex University appear to be on the way to ___1___ how the mosquito, carrier of diseases such as malaria and yellow fever, homes in on its target. The problem is that they have found t
Are some people born clever, and others born stupid? Or is intelligence developed by our environment and our experiences? Strangely enough, the answer to both these questions is yes. To some extent ou
Climate, more than any other single factor, __1__the distribution of life on Earth. Climatic boundaries establish the limits within which organisms can survive. Plants, even more than animals, must be
More attention was paid to the quality of production in France at the time of Rene Coty. Charles Deschanel was then the financial minister. He stressed that workmanship and quality were more important
As a company executive(总经理) who spent ten years in federal service, I am often asked what I regard as the biggest difference between working for the government and working for a private company.
Once you're prepared for a situation, you're 50 percent of the way toward overcoming nervousness. The other 50 percent is the physical and mental control of nervousness; adjusting your attitude so you