更多"Arsenic, a naturally occurring pois"的相关试题:
[单项选择]Arsenic, a naturally occurring poison and carcinogen found in ground water, is strongly linked to adult-onset diabetes, U. S. researchers said on Tuesday. Odorless, tasteless, colorless and easily soluble in water or wine, arsenic has long been a feared poison. A heavy dose is detectable in a corpse, but researchers say small amounts of arsenic may sicken people gradually.
Dr. Ana Navas-Aeien and colleagues at Johns Hopkins University in Baltimore found a " relatively strong " association between commonly found levels of arsenic in urine and type 2 diabetes in a study of American adults. " It seems there is maybe no safe level of arsenic. " Navas-Acien said in a telephone interview. " Worldwide it’s a huge problem, " she said. " As water becomes a scarce resource. the situation becomes even more serious. "
Arsenic raises the risk for cancers of the bladder, lung, kidney, skin and, possibly, the pros tate, Navas-Acien said. The 20 percent of nearly 800 study participants who
A. smell
B. taste
C. poison
D. color
[单项选择]Naturally occurring chemicals cannot be newly patented once their structures have been published. Before a naturally occurring chemical compound can be used as a drug, however, it must be put through the same rigorous testing program as any synthetic compound, culminating in a published report detailing the chemical"s structure and observed effects.
If the statements above are true, which of the following must also be true on the basis of them
A. Any naturally occurring chemical can be reproduced synthetically once its structure is known
B. Synthetically produced chemical compounds cannot be patented unless their chemical structures are made public
C. If proven no less effective, naturally occurring chemicals are to be preferred to synthetic compounds for use in drugs
D. Once a naturally occurring compound has been approved for use as a drug, it can no longer be newly patented
E. A naturally occurring chemical cannot be patented unless its effectiveness as a drug has been rigorously established
[单项选择]Revolutionary innovation is now occurring in all scientific and technological fields. This wave of unprecedented change is driven primarily by advances in information technology, but it is much larger in scope. We are not dealing simply with an Information Revolution but with a Technology Revolution.
To anticipate developments in this field, the George Washington University Forecast of Emerging Technologies was launched at the start of the 1990s. We have now completed four rounds of our Delphi survey — in 1990, 1992, 1994, and 1996 — giving us a wealth of data and experience. We now can offer a reasonably clear picture of what can be expected to happen in technology over the next three decades.
Time horizons play a crucial role in forecasting technology. Forecasts of the next five to ten years are often so predictable that they fall into the realm of market research, while those more than 30 or 40 years away are mostly speculation. This leaves a 10- to 20-year window in
A. foresee future technologies
B. influence future technologies
C. provide new technologies
D. design new technologies
