单选题{{B}}第三篇{{/B}} {{B}} High Stress May Damage Memory{{/B}} According to a report issued in May 1998, elderly people who have consistently high blood levels of cortisol don't score as well on memory tests as their peers with lower levels of the stress hormone. What's more, high levels of cortisol are also associated with shrinking of the hippocampus, a region of the brain that plays a key role in learning and memory. The findings suggest that even cortisol levels in the normal, "healthy" range can actually accelerate brain aging. The study results "now provide substantial evidence that long-term exposure to adrenal stress hormones may promote hippocampal aging in normal elderly humans," write Nada Porter and Philip Land- field of the University of Kentucky in Lexington in their editorial Cortisol is a hormone released in response to stress by the adrenal glands, which sit on top of the kidneys. Over a S to 6-year period, Dr. Sonia Lupien and his colleagues measured 24-hour cortisol levels in 51 healthy volunteers ,most of whom were in their 70s. Despite wide variation in cortisol levels, the participants could be divided into three subgroups :those whose cortisol progressively increased over time and was currently high (increasing/high) ~ those whose cortisol progressively increased over time and was currently moderate (increasing/moderate); and subjects whose cortisol decreased, but was currently moderate (decreasing/moderate). The researchers tested the volunteers' memory on six people in the increasing/high category and five people in the decreasing/moderate group. The groups did not differ on tests of immediate memory, but the increasing/high cortisol group had other memory problems compared with those in the decreasing/ moderate group. The researchers also found that the total volume of the hippocampus in those in the increasing/high group was 14％lower than those in the decreasing/moderate group, although there were no differences in other brain regions. The results suggest that "...brain aging can be accelerated by levels of adrenal hormones that are not generally regarded as pathological and that variation within this normal range is related to variation in the rate of brain aging," write Porter and Landfield. "This further suggests that chronic stress may accelerate the worsening of hippocampus. '

单选题The thief was finally captured two miles away from the village.

单选题Insurance Whole life is permanent insurance protection that protects you for your whole life, from the day you purchase the policy until you die, as long as you pay the premiums (保险费). Whole life can be a solid foundation. Upon this foundation you can build a long-term financial plan, because it guarantees lifetime protection for your family or business. Whole life insurance provides basic insurance protection, plus Mortgage protection, Estate preservation, Retirement funding, Charitable giving, Business needs... A life insurance agent will help you determine an amount of insurance needed to protect your family or business in the event of your death. Generally after the first year, the policy begins to increase cash value. The amount of cash value in your policy usually increases every year. This money can be used to help purchase a home, fund a child's education, add to retirement income, or for any other purpose. You may also choose to leave it in the policy and allow it to grow. A whole life policy can earn dividends. Dividends are determined by the company's board of directors each year and are not guaranteed. When a dividend is payable, you may choose to take it in cash, use it to buy more insurance or to pay or reduce your premiums. When you die, the company will pay your beneficiaries the death benefit, usually the face amount of the policy plus any dividend. This money is generally received by the beneficiaries free from income tax.

单选题Paul Revere made his famous midnight ride to warn American patriots that the enemy was coming. A. admonish B. alert C. ensure D. remind

单选题According to the passage, the adrenalin level in your blood rises when

单选题A seed planted in the sensitive lining of an oyster begins a perpetual coating process that forms a pearl.

单选题When he spoke, she had an unpleasant insight into what life would be like as his wife. A. perception B. precept C. precede D. preceptor

单选题The brain controls the other body activities through

单选题He hated coming home to the empty house.A. dislikedB. wishedC. suggestedD. disgusted

单选题Police officers working on the murder have questioned hundreds of families.A. askedB. demandedC. inquiredD. requested

单选题They had a far better yield than any other farm miles away around this year.

单选题I recommend you buy a computer.

单选题Language and Communication A language is a signaling system which operates with symbolic vocal sounds(语声), and which is used by a group of people for the purpose of communication. Let's look at this (51) in more detail because it is language, more than anything else, (52) distinguishes man from the rest of the physical world. Other animals, it is true, communicate with one another by (53) of cries, for example, many birds utter (54) calls at the approach of danger; monkeys utter (55) cries, such as expressions of anger, fear and pleasure. (56) these various means of communication differ in important ways from human language. For instance, animals' cries do not (57) thoughts and feelings clearly. This means, basically, that they lack structure. They lack the kind of structure that (58) us to divide a human utterance into (59) We can change an utterance by replacing one word in it with (60) : a good illustration of this is a soldier who can say, e.g., "tanks approaching from the north", (61) who can change one word and say "aircraft approaching from the north" or "tanks approaching from the west"; but a bird has a single alarm cry, (62) means "danger!" This is why the number of signals that an animal can make is very limited: the great tit (山雀) is a case (63) point; it has about twenty different calls, (64) in human language the number of possible utterances is limitless. It also explains why animal cries are very (65) in meaning.

单选题It is said the houses along this street will soon be demolished.A. pulled downB. pulled upC. pulled offD. pulled in

单选题He {{U}}purchased{{/U}} a ticket and went up on the top deck. A. bought B. took C. showed D. made

单选题I was deeply impressed by the Uassurance/U with which the student answered all my questions.

单选题A tuning fork is a narrow, two-pronged steel bar that when tuned to a specific musical pitch retains its tuning almost indefinitely .

单选题The nursery is bright and cheerful .

单选题Many students were absent, notably the monitor.

单选题According to Dr . David Faxon, the self-contained heart is