Text 3 AIDS is one of the most fatal and rampant diseases that deprives of hundreds of thousands of lives each year all over the world, and the condition in African countries is much worse for lack of medicine, education as well as preventive measures. Scientists and researchers have never ceased their efforts to halt the wide spreading tendency of this infecting disease, unfortunately, till now, they have not invented any effective vaccine. Last week, an experimental AIDS vaccine tested in Thailand on some 2,500 drug users failed to protect them from becoming infected with HIV, declared VaxGen Inc., the vaccine’s developer. The pool results were widely expected since VaxGen Inc. had said earlier that its vaccine did not work in a larger North American study. Most AIDS researchers agree that vaccines will be the only effective way to control a virus that has killed 28 million people and infected 42 million more worldwide. Two dozen other vaccines are being tested on
A. It is incurable.
B. The international public health community has not done enough to control the disease.
C. Vaxgen's vaccine is more effective than others.
D. It is still hopeful to cure AIDS.
Text 3
AIDS is one of the most fatal and rampant diseases that deprives of hundreds of thousands of lives each year all over the world, and the condition in African countries is much worse for lack of medicine, education as well as preventive measures. Scientists and researchers have never ceased their efforts to halt the wide spreading tendency of this infecting disease, unfortunately, till now, they have not invented any effective vaccine. Last week, an experimental AIDS vaccine tested in Thailand on some 2,500 drug users failed to protect them from becoming infected with HIV, declared VaxGen Inc., the vaccine’s developer. The pool results were widely expected since VaxGen Inc. had said earlier that its vaccine did not work in a larger North American study.
Most AIDS researchers agree that vaccines will be the only effective way to control a virus that has killed 28 million people and infected 42 million more worldwide.
Two dozen other vacci
A. It is incurable.
B. The international public health community has not done enough to control the disease.
C. Vaxgen's vaccine is more effective than others.
D. It is still hopeful to cure AIDS.
Text 3 AIDS is one of the most fatal and rampant diseases that deprives of hundreds of thousands of lives each year all over the world, and the condition in African countries is much worse for lack of medicine, education as well as preventive measures. Scientists and researchers have never ceased their efforts to halt the wide spreading tendency of this infecting disease, unfortunately, till now, they have not invented any effective vaccine. Last week, an experimental AIDS vaccine tested in Thailand on some 2,500 drug users failed to protect them from becoming infected with HIV, declared VaxGen Inc., the vaccine’s developer. The pool results were widely expected since VaxGen Inc. had said earlier that its vaccine did not work in a larger North American study. Most AIDS researchers agree that vaccines will be the only effective way to control a virus that has killed 28 million people and infected 42 million more worldwide. Two dozen other vaccines are being tested on
A. In Thailand
B. In North America
C. At Brisbane
D. In Africa
Text 4
Most economists in the United States seem excited by the spell of the free market. Consequently, nothing seems good or normal that does not accord with the requirements of the free market. A price that is determined by the seller or, for that matter, established by anyone other than the aggregate of consumers seems harmful. Accordingly, it requires a major act of will to think of price-fixing (the determination of prices by the seller) as both "normal" and having a valuable economic function. In fact, price-fixing is normal in all industrialized societies because the industrial system itself provides, as an effortless consequence of its own development, the price-fixing that it requires. Modern industrial planning requires and rewards great size. Hence, a comparatively small number of large firms will be competing for the same group of consumers. That each large firmwill act with consideration of its own needs and thus avoid selling its products fo
A. a profitable result of economic development.
B. an inevitable result of the industrial system.
C. the result of a number of carefully organized decisions.
D. a phenomenon common to industrialized and non-industrialized societies.
Text 3
Most growing plants contain much more water than all other materials combined. C. R. Bames has suggested that it is .as proper to term the plant a water structure as to call a house composed mainly of brick a brick building. Certainly it is that all essential processes of plant growth and development occur in water. The mineral elements from the soil that are usable by the plant must be dissolved in the. soil solution before they can be taken into the root. They are carried to all parts of the growing plants and are built into essential plant materials while in a dissolved state.
The carbon dioxide (CO2) from the air may enter the leaf as a gas but is dissolved in water in the leaf before it is combined with a part of the water to form simple sugars -- the base material from which the plant body is mainly built. Actively growing plant parts are generally 75 to 90 percent water. Structural parts of plants, such as wood
A. a plant efficiently utilizes most of the water it absorbs
B. carbon dioxide is the essential substance needed for plant development
C. a plant needs more water than is found in its composition
D. the stronger the wind, the more the water vapor loss'
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