I wish that John would write more（ ） . I can never read his notes and letters.

Thanks to some help from professors at the university in Canberra，the Australian authorities are letting me to bring my biological samples into the country without the usual three-week quarantine.

Three days ago I received an e-mail from the conference organizers apologizing the last-minute changes in the schedule; they sounded genuinely embarrassed at the disorder in their planning.

How （ ）do you travel to Shanghai on business?

（1） to the weather report on the radio, it’s raining in Shanghai, but that （2）be true.I was just on the phone to Shanghai and the（3） I spoke with said it was sunny there.句意: 听收音机上的天气预报说伤害正在下雨，但那不可能是真的。我刚和上海的一个人通了电话，其说上海正出太阳。

The woman, 69 years old and still active as a professor at Harvard University, told a research team that she had begun to find it hard to recall the names of ever faculty members. Not long ago she had forgotten her classroom number when asking for a slide projector to be sent up. She had one anxious question for the research team, assembled to study the normal course of mental aging: “Am I losing my ability to remember, and perhaps even to think clearly?”That question is the principal focus of a new wave of scientific inquiry on the decline in mental ability with age. The findings are challenging some basic assumptions, like the belief that such decline is a natural part of the aging process, irrespective of general health.From 20 to 30 percent of people in their 80s who volunteer for cognitive testing perform as well as volunteers in their 30s and 40s, who are presumably in their mental prime. The intellectual and creative productivity in later life of certain artists and intellectuals may represent not so much an exception as an ideal, some experts now say.Dr KW Schaie, a psychologist at Pennsylvania State University, is the director of a major study of normal mental decline in the elderly. For over 35 years, his study has been following more than 5000 men and women who have been tested regularly. Dr Schaie’s investigations seek to fill a gap in gerontological research, which, according to Dr Jack Rowe, president of the Mount Sinai School of Medicine and a leading expert in the field, has focused on disease and disability, and neglected the prospects of maintaining high functioning in old age. Dr Rowe heads a research network on successful aging sponsored by the MacArthur Foundation. In an interview he pointed out that gerontologists have focused on ‘"the 6 to 15 percent of the elderly who are frail and then lumped everyone else together as normal. But there is a huge variation from person to person among older people: the older a group gets, the less like each other people in it become.”Dr Schaie’s most recent findings were reported this month in The American Psychologist. Although the study’s results show abilities begin to decline gradually in the middle to late 60s and accelerate in the late 70s. The rate of decline differs for various mental faculties and differs in men and women. The sharpest declines are seen in basic mathematics. By their late 80s, both men and women were only about half as adept in basic math as they had been in their 50s. For men, the least decline shown is in spatial orientation, for example, in reading a map correctly. By the late 80s, it had dropped by only about one-eighth on average.For women, the most enduring mental skill is inductive reasoning, assessing the information in a timetable, for instance. As women reached their late 80s, it had dropped just over one-eighth from its height in middle age. One of the drastic declines for women proved to be in verbal comprehension, while that ability dropped relatively little into the 70s, it plummeted by about one-quarter during the 80s. For men, the decline was slight in those years.Another study, this one by Dr Richard Mons, a psychologist at Mount Sinai Medical School who is the acting director of a research consortium on normal memory loss and aging sponsored by the Charles
A. Dana Foundation, has found that different kinds of memory differ in their vulnerability to aging. “Crystallized” memory, ie, vocabulary or other knowledge accumulated over the years holds up very well into old age. “Fluid” memory, on the other hand, the ability to add new information to memory or to recall something that happened recently is more prone to decline, beginning in the 60s. He found little decline in very short-term memory, like remembering a telephone number just looked up.A pair of Harvard psychologists, Douglas Powell and Kean Whitla, have designed a computerized test of mental skills like long-term and short-term memory, attention, reasoning and calculation; they reported the test in the February issue of Current Directions in Psychological Sc