【正文】 many different directions(C) more slowly than scientists previously believed(D) further in summer than in winterPassage 4 Here in the United States, before agricultural activities destroyed the natural balance, there were great migrations of Rocky Mountain locusts (Melanoplus spretus). Great migrating hordes of these insects once darkened the skies on the plains east of the Rockies where crops were often destroyed。 the worst years were those from 1874 to 1877. One of these migrating swarms was estimated to contain 124 billion locusts. During another migration in Nebraska it was estimated that the swarm of locusts averaged half a mile high and was 100 miles wide and 300 miles long. Usually, these swarms take oft from the ground against the wind, but, once airborne, they turn and fly with it. warm convection currents help to lift them, often to great heights. During the great locust plagues the situation in Nebraska became so serious that the original state constitution had to be rewritten to take care of the economic problems. The new document was known as The Grasshopper Constitution. It is now believed that these locusts were a migratory form or phase of the lesser migratory locust, which is still mon there. In this respect, the North American migratory locusts resemble their African relatives. In both regions the migratory forms arise as a result of crowding and climatic factors. Migratory forms are apparently natural adaptations which bring about dispersal when locust populations bee too crowded. Fortunately for our farmers the migratory form the socalled spretus species no longer seems to occur regularly, although there was a serious outbreak as late as 1938 in midwestern United States and Canada. Actually, there is no reason why the destructive migratory form might not again appear if circumstances should bee favorable.1. Which of the following is the best title for the passage?(A) The Life Cycle of Locusts(B) Migratory Locusts in the United States(C) Locust Plagues in Nebraska(D The Reproductive Capability of the Locust2. According to the passage the worst destruction by locusts in the plains area east of the Rockies occurred during the(A) eighteenth century(B) early nineteenth century(C) late nineteenth century(D) twentieth century3. One of the migrating swarms mentioned in the passage averaged how many miles in length(A) 100(B) 124 (C) 187(D) 3004. It can be inferred from the passage that the state constitution of Nebraska was rewritten in order to(A) make the constitution more understandable to the public(B) encourage farmers to leave the state(C) solve difficulties that resulted from loss of crops (D) provide for a regular census of the locust population5. According the passage, North American and African migratory locusts are similar in that(A) they always travel toward mountainous regions(B) their destructive activities occur only in plains areas(C) climates affect their development (D) they are both mentioned in state constitutions6. Which of the following is NOT mentioned in the passage as influencing the migration of locusts?A) Darkness(B) Agricultural activities(C) Warm air currents(D) Overcrowding7. The passage supports which of the following conclusions?(A) the outbreak of locusts in 1938 was more serious than any other in history.(B) Nebraska farmers had no locust problems in the years 1874 1877.(C) There is a possibility that crops in the United States might be destroyed by locusts in the future.(D)There is a chance that African migratory locusts may make their way to the United States.Passage 5 Artificial flowers are used for scientific as well as for decorative purposes. They are made from a variety of materials, such as wax and glass, so skillfully that they can scarcely be distinguished from natural flowers. In making such models, painstaking skill and artistry are called for, as well as thorough knowledge of plant structure. The collection of glass flowers in the Botanical Museum of Harvard University is the most famous in North America and is widely known throughout the scientific world. In all, there are several thousand models in colored glass, the work of two artist naturalists, Leopold Blaschka and his son Rudolph. The intention was to have the collection represent at least one member of each flower family native to the United States. Although it was never pleted, it contains more than seven hundred species representing 164 families of flowering plants, a group of fruits showing the effect of fungus diseases, and thousands of flower parts and magnified details. Every detail of these is accurately reproduced in color and structure. The models are kept in locked cases as they are too valuable and fragile for classroom use.1. Which of the following is the best title for thepassage.(A)An Extensive Collection of Glass Flowers(B ) The Lives of Leopold and Rudolph Blaschka(C) Flowers Native to the United States. (D) Materials Used For Artificial Flowers2. Which of the following statements about Leopold and Rudolph Blaschka is true?(A) They were brothers.(B) They were artists.(C) They were florists.(D) They were farmers. can be inferred from the passage that the goal of Leopold and Rudolph Blaschka was to (A) create a botanical garden where only exotic flowers grew(B) do a thorough study of plant structure (C) make a copy of one member of each United States flower family(D) show that glass flowers are more realistic than wax flowers4. In line 9, the word it refers to which of the following phrases?(A) The intention (line 8)(B) the collection (line 8)(C) one member(line 8)(D) each flower family(lines S~9)5. Which of the following is NOT included in the display at the Botanical Museum of Harvard University?(A) Models of 164 families of flowering plants(B) Magnified details of flower parts(C) Several species o