Despite its enormous food potential, little effort was made until recently to farm plankton as we farm grasses on land. Now marine scientists have at last begun to study this possibility, especially as the sea’s resources loom even more important as a means of feeding an expanding world population.

　　No one yet has seriously suggested that “planktonburgers” may soon become popular around the world. As a possible farmed supplementary food source, however, plankton is gaining considerable interest among marine scientists.

　　One type of plankton that seems to have great harvest possibilities is a tiny shrimplike creature called krill. Growing to two or three inches long, krill provide the major food for the giant blue whale, the largest animal ever to inhabit the Earth. Realizing that this whale may grow 100 feet and weigh 150 tons at maturity, it is not surprising that each one devours more than one ton of krill daily.

　　Krill swim about just below the surface in huge schools sometimes miles wide, mainly in the cold Antarctic. Because of their pink color, they often appear as a solid reddish mass when viewed from a ship or from the air. Krill are very high in food value. A pound of these crustaceans contains about 460 calories—about the same as shrimp or lobster, to which they are related.

　　If the krill can feed such huge creatures as whales, many scientists reason, they must certainly be contenders as new food source for humans.

　　1.Which of the following best portrays the organization of the passage?

　　A.The author presents the advantages and disadvantages of plankton as a food source.

　　B.The author quotes public opinion to support the argument for farming plankton.

　　C.The author classifies the different food sources according to amount of carbohydrate.

　　D.The author makes a general statement about plankton as a food source and then moves to a specific example.

　　2.According to the passage, why is plankton regarded to be more valuable than land grasses?

　　A.It is easier to cultivate.

　　B.It produces more carbohydrates.

　　C.It does not require soil.

　　D.It is more palatable.

　　3.Why does the author mention “planktonburgers”?

　　A.To describe the appearance of one type of plankton.

　　B.To illustrate how much plankton a whale consumes.

　　C.To suggest plankton as a possible food sources.

　　D.To compare the food values of beef and plankton.

　　4.What is mentioned as one conspicuous feature of krill?

　　A.They are the smallest marine animals.

　　B.They are pink in color.

　　C.They are similar in size to lobsters.

　　D.They have grass like bodies.

　　5.The author mentions all of the following as reasons why plankton could be considered a human food source except that it is ___.

　　A.high in food value.

　　B.in abundant supply in the oceans.

　　C.an appropriate food for other animals.

　　D.free of chemicals and pollutants.

　　答案：DBCBD

　　Acting is such an over-crowded profession that the only advice that should be given to a young person thinking of going on the stage is "Don't!". But it is useless to try to discourage someone who feels that he must act, though the chances of his becoming famous are slim. The normal way to begin is to go to a drama school. Usually only students who show promise and talent are accepted, and the course lasts two years. Then the young actor or actress takes up work with a repertory company, usually as an assistant stage manager. This means doing everything that there is to do in the theatre: painting scenery, looking after the furniture, taking care of the costumes, and even acting in very small parts. It is very hard work indeed. The hours are long and the salary is tiny. But young actors with the stage in their blood are happy, waiting for the chances of working with a better company, or perhaps in films or television.

　　Of course, some people have unusual chances which lead to fame and success without this long and dull training. Connie Pratt, for example, was just an ordinary girl working in a bicycle factory. A film producer happened to catch sight of her one morning waiting at a bus stop, as he drove past in his big car. He told the driver to stop, and he got out to speak to the girl. He asked her if she would like to go to the film studio to do a test, and at first she thought he was joking. Then she got angry and said she would call the police. It took the producer twenty minutes to tell Connie that he was serious. Then an appointment was made for her to go to the studio the next day. The test was successful. They gave her some necessary lessons and within a few weeks she was playing the leading part opposite one of the most famous actors of the day. Of Course, she was given a more dramatic name, which is now world-famous. But chances like this happen once in a blue moon!

　　52. According to the passage, the main reason why young people should be discouraged from becoming actors is ______.

　　A) actors are very unusual people B) the course at the drama school lasts two years

　　C) acting is really a hard job D) there are already too many actors

　　53. An assistant stage manager's job is difficult because he has to ______.

　　A) do all kinds of stage work B) work for long hours C) wait for a better company D) act well

　　54. According to the context, the sentence "But young actors with the stage in their blood are happy" at the end of the first paragraph means ______.

　　A) they don't care if their job is hard B) they like the stage naturally C) they are born happy D) they are easily satisfied

　　55. Conie Pratt soon became a famous actress after ______.

　　A) learning some lessons about the art of speaking B) playing her part in the "Blue Colored Moon"

　　C) successfully matching the most famous actors D) acting a leading part with a most famous actor at that time

　　56. The phrase "once in a blue moon" in last line refers to ______.

　　A) all at once B) once for a long time C) once in a while D) once and for all

　　答案DABDB