In this text the authors main intent is to______.
A．underscore the difficulties related to aging
B．critique different theories of mental decline in old age
C．argue that old age need not be a barrier to great accomplishments
D．understand how people can counter the impacts of aging on mental faculties

未分类题It is indicated in the first two paragraphs that______.A．the debt proportion in GDP of emerging economies is much higher than that of advanced economiesB．all advanced economies are facing low growth and high unemployment caused by the financial crisisC．public finances are a reflection of the difference in growth rate between emerging and advanced economiesD．economic crisis is less severe and interrelated now than before

未分类题The underlined word 'volatility' in Paragraph 2 refers to______.A．stabilityB．fluctuationC．surgingD．filling

未分类题Currently, most job opportunities for high school students and graduates are available in______.A．the high-tech sectorB．temporary employmentC．retail storesD．amusement parks

未分类题According to the text, most great thinkers and artists______.A．were productive even in their later yearsB．were most successful before the age of 30C．made contributions regardless of ageD．contributed the most before old age

未分类题如果一幅图像能够表示的颜色数量为256种，则该图像的量化位数是()位。A. 4B.1C.256D. 8