38. Amateur scientists have long been attracted to the discipline of astronomy, and professional
astronomers are frequently supportive of their contribution to the science. Indeed, amateur astronomers have often been the first to spot an uncharted comet or star. Until now, the required scientific equipment has, unfortunately, been largely very expensive, varying
according to the intricacy and size of the apparatus. According to some scientists, however, the spread of new, cheap technology, particularly in information and date management, promises to dramatically change and facilitate amateur-professional interaction, and collaboration. Amateur-professional collaboration will contribute to the advancement of astronomy. T C Following the spread of new, and cheaper technology, more amateur scientists are
collaborating with professionals. C T
39. Scientists believe we are experiencing a dramatic change in the overall climate system,
verified by the 10-15 cm rise in sea levels over the last 100 years and the increases in severe weather conditions. Although climate change occurs naturally, scientists believe human
activities have led to increased carbon dioxide, methane and nitrous oxide concentrations(二
氧化碳，甲烷和一氧化二氮浓度), leading to climate changes and, in turn, observed
increases in sea levels, atmospheric temperatures, and erratic weather systems. This means that today’s climate shift differs dramatically from previous shifts in climates in both magnitude and rate. Scientific research suggests that advancing sea levels, rising
temperatures and severe weather conditions caused by climate change will result in a host of negative consequences such as a threat to international trade patterns, an increase in the movement of tropical disease, and an increased risk of forest fires and landslides.
Only the difference in velocity distinguishes current climates shifts from previous shifts. F The enormity of alterations to our climate system has never been experienced by human beings before. T People will catch more tropical disease due to climate change. C
40. Human mortality, whilst consisting of unpredictable individual events, has a statistical regularity when averaged across a large group. This makes possible a whole host of products, of which the annuity is one. The price of an annuity paying a fixed regular income for life is based upon the statistical life expectancy of the purchaser at the time the annuity is to begin.
The company selling the annuity will benefit from all those customers that die earlier than
predicted, while customers are attracted by the prospect of guaranteed income for as long as they live. Annuities have the disadvantage that the capital invested is unrecoverable (i.e. upon the death of annuitant nothing is left for the heirs), but that fact also enables annuities
to guarantee higher payments than could be obtained if the same sum of money were invested at interest. The heirs of a person who buy an annuity tend to be against the purchase. C
Essentially, the purchaser of an annuity is gambling that they will live long enough to receive a good return on their investment. C