[单项选择]The indoor swimming pool seems to be a great deal more luxurious than （）.
A. is necessary
B. being necessary
C. to be necessary
D. it is necessary

[单项选择]The indoor swimming pool seems to be a great deal more luxurious than （　）.
A. is necessary
B. being necessary
C. to be necessary
D. it is necessary

[单项选择]There is a great deal of geographical variation in the frequency of many surgical procedures—up to tenfold variation per hundred thousand between different areas in the numbers of hysterectomies, prostatectomies, and tonsillectomies. To support a conclusion that much of the variation is due to unnecessary surgical procedures, it would be most important to establish which of the following
A. A local board of review at each hospital examines the records of every operation to determine whether the surgical procedure was necessary.
B. The variation is unrelated to factors (other than the surgical procedures themselves) that influence the incidence of diseases for which surgery might be considered.
C. There are several categories of surgical procedure (other than hysterectomies, prostatectomies, and tonsillectomies) that are often performed unnecessarily.
D. For certain surgical procedures, it is difficult to determine after the operation whether the procedures were necessary or whether alternative treatment would have succeeded.
E. (E) With respect to how often they are performed unnecessarily, hysterectomies, prostatectomies, and tonsillectomies are representative of surgical procedures in general.

[单项选择]Scientists have learned a great deal about the kinds of food people need. They say that there are several kinds of food that people should eat every day. What are these classes of food They are 1) green vegetables of all kinds, such as string beans, peas, lettuces, and cabbages; 2) fruit, such as apples, peaches and bananas; 3) other vegetables, examples of these are beets, onions, carrots, tomatoes and so on; 4) meat of all kinds, fish and eggs; 5) milk and food made from milk, such as butter, cheese and ice-cream; 6) bread or cereal. Rice is also in this class of food.
People in different countries and different areas of the world eat different kinds of things. Scientists say that none of these differences are really important. It doesn’t matter whether food is eaten raw or cooked, canned, or frozen. It doesn’t matter if a person eats dinner at four o’clock in the afternoon or at eleven o’clock at night. The important thing, they say, is that every day a person should eat someth
A. The kinds of food that should be eaten every day.
B. Whether to eat food raw or cooked.
C. When to eat food every day.
D. How much food to eat every day.

[填空题]Although we already know a great deal about influenza, it is difficult for epidemiologists (流行病学家), who study infectious disease, to (36) when and where the next flu epidemic will occur, and how (37) it will be. There are three kinds of influenza virus, known as A, B and C. Influenza C virus is relatively stable and causes mild (38) that do not spread far through the population. The A and B types are (39) , and are responsible for the epidemics that cause frequent concern. Following any virus attack, the human body builds up antibodies which confer (给予) immunity to that strain of virus, but a virus with the capacity to change its character is able to bypass this (40) . Variability is less developed in the influenza B virus, which affects only human beings. An influenza B virus may cause a widespread but will have little effect if (41) into the same community soon afterwards, since nearly everyone will have built up