听力原文：M: Are you going with us to the concert, Helen?
W: Maybe. I'm not sure.
M: You'd better make up your mind. We're leaving at six.
W: No, I don't think I will. I've got too much to do. I'm going to stay home.
Why won't Helen go to the concert?

Questions 36 to 40 are based on the following passage. In the United States, the need to protect plant and animal species has become a highly controversial and sharply political issue since the passage of the Endangered Species Act in 1973. The act, designed to protect species’ living areas, and policies that preserve land and forests compete with economic interests. In the 1990’s, for example, the woodcutters in the Western United States were challenged legally in their attempt to cut trees for timber in the Cascade Mountains. The challenge was mounted to protect the endangered spotted owl (猫头鹰), whose remaining population occupies these forests and requires the intact, ancient forest for survival. The problematic situation set the interests of environmentalists against those of corporations and of individuals who stood to lose jobs. After months of debate and legal battles, the fate of the woodcutters-and the owls-was still undecided in mid-1992.Similar tensions exist between the developed and the developing nations. Many people in industrialized nations, for example, believe that developing nations in tropical regions should do more to protect their rain forests and other natural areas. But the developing countries may be impoverished (使穷困), with populations growing so rapidly that using the land is a means to temporarily avoid worsening poverty and starvation.Many of the changes to Earth that concern scientists have the potential to rob the planet of its biological richness. The destruction of Earth’s ozone layer (臭氧层), for example, could contribute to the general process of impoverishment by allowing ultra-violet rays to harm plants and animals. And global warming could wipe out species unable to quickly adapt to changing climates. Clearly, protecting will come only through coordinated international efforts to control human population, stabilize the composition of the atmosphere, and preserve intact Earth’s complex web life.第36题：Why does the author say that the protection of endangered species is a highly controversial issue?

A.
B.
Many
C.
第36题：Why
D.
B)
E.
C)
F.
D)
G.

点击查看答案

Questions 26 to 30 are based on the following passage. There are some each phenomena you can count on, but the magnetic field, someday is not of them. It fluctuates in strength, drifts from its axis, and every few 100,000 years undergo, dramatic polarity reversal-a period when North Pole becomes South Pole and South Pole becomes North Pole. But how is the field generated, and why is it so unstable?Groundbreaking research by two French geophysicists promises to shed some light on the mystery. Using 80 metres of deep sea sediment (沉淀物) core, they have obtained measurements lots of magnetic-field intensity that span 11 polarity reversals and four million years. The analysis reveals that intensity appears to fluctuate with a clear, well-defined rhythm. Although the strength of the magnetic field varies irregularly during the short term, there seems to be an inevitable long-term decline preceding each polarity reversal. When the poles flip—a process that takes several hundred thousand years-the magnetic field rapidly regains its strength and the cycle is repeated.The results have caused a stir among geophysicists. The magnetic field is thought to originate from molten (熔化的) iron in the outer core, 3,000 kilometers beneath the earth’s surface. By studying mineral grains found in material ranging from rocks to clay articles, previous researchers have already been able to identify reversals dating back 170 million years, including the most recent switch 730,000 years ago. How and why they occur, however, has been widely debated. Several theories link polarity flips to external disasters such as meteor (陨星) impacts. But Peter Olson, a geophysicist at the Johns Hopkins University in Baltimore, says this is unlikely if the French researchers are right. In fact, Olson says intensity that predictably declines from one reversal to the next contradicts 90 percent of the models currently under study. If the results prove to be valid geophysicists will have a new theory to guide them in their quest to understand the earth’s inner physics. It certainly points the direction for future research.第26题：Which of the following titles is most appropriate to the passage?

A.
B.
第26题：Which
C.
B)
D.
C)
E.
D)
F.

点击查看答案