【正文】 the second,often,is a tiring task. 31. According to the text,adult persons usually ［ A］ stress the settlement of bigger problems. ［ B］ focus their attention on great issues. ［ C］ overlook the remembrance of trivial things. ［ D］ suffer memory decline related to age. 32. According to new research,it s distinct that ［ A］ our brain cells can be producible. 此資料來自企業(yè) ［ B］ our memory may be renewable. ［ C］ most mental illnesses are curable. ［ D］ brain mending methods are available. 33. The phrase “nuts and bolts” in most probably means ［ A］ basic structures. ［ B］ plex tasks. ［ C］ practical aspects. ［ D］ working parts. 34. As asserted by researchers,our inability to memorize words or names mainly ［ A］ results from the declining efficiency of brain cells. ［ B］ results in the brain s liability to radical interference. ［ C］ consists of different mental disorders. ［ D］ consists in various emotional problems. 35. Experts suggest that the best way to avoid memory failures is ［ A］ to take more dietary supplements. ［ B］ to keep mental function alive. ［ C］ to find an intellectual occupation. ［ D］ to do more intellectual exercises. Text 4 Nonindigenous (nonnative) species of plants and animals arrive by way of two general types of pathways. First, species having origins outside the United States may enter the country and bee established either as freeliving populations or under human cultivation— for example, in agriculture, horticulture, aquaculture, or as pets. Some cultivated species 此資料來自企業(yè) subsequently escape or are released and also bee established as freeliving populations. Second, species of either . or foreign origin and already within the United States may spread to new locales. Pathways of both types include intentional as well as unintentional species transfers. Rates of species movement driven by human transformations of natural environments as well as by human mobility— through merce, tourism, and travel— greatly exceed natural rates by parison. While geographic distributions of species naturally expand or contract over historical time intervals(tens to hundreds of years), species ranges rarely expand thousands of miles or across physical barriers such as oceans or mountains. Habitat modification can create conditions favorable to the establishment of nonindigenous species. Soil disturbed in construction and agriculture is open for colonization by nonindigenous weeds, which in turn may provide habitats for the nonindigenous insects that evolved with them. Humangenerated changes in fire frequency, grazing intensity, as well as soil stability and nutrient levels similarly facilitate the spread and establishment of nonindigenous plants. When human changes to natural environments span large geographical areas, they effectively create passages for species movement between previously isolated locales. The rapid spread of the Russian wheat aphid to fifteen states in just two years following its 1986 arrival has been attributed in part to the prevalence of alternative host plants that are available when wheat is not. Many of these are nonindigenous grasses remended for planting on the forty million or more acres enrolled in the . Department of Agriculture Conservation Reserve Program. A number of factors perplex quantitative evaluation of the relative importance of various entry pathways. Time lags often occur between establishment of nonindigenous species and their detection, and tracing the pathway for a longestablished species is difficult. Experts estimate that nonindigenous weeds are usually detected only after having been in the country for thirty years or having spread to at least ten thousand acres. In addition, federal port inspection, although a major source of information on nonindigenous species pathways, especially for agriculture pests, provides data only when such species enter via closelyexamined routes. Finally, some parisons between pathways defy quantitative analysis— for example, which is more “important” ： the entry path of one very harmful species or one by which many but less harmful species enter the country? 此資料來自企業(yè) of the following statements about species movement is best supported by the text? ［ A］ Human factors affect species movement rates more than its longterm amount. ［ B］ Natural expansions of species account for their slow natural contractions. ［ C］ Natural environments created by human activities contribute much to species movement. ［ D］ Longrange movement of species depends on the geographic extent of human mobility. 37According to the text, the . Department of Agriculture ［ A］ contributed to the fast distribution of the Russian wheat aphid to broad areas. ［ B］ failed to isolate the Russian wheat aphid in limited locales. ［ C］ provides data about foreign species entering the country by regulated routes. ［ D］ is responsible for introducing harmful plants onto federal lands. can be inferred that all of the following affect the movement of species EXCEPT ［ A］ earth fertility. ［ B］ import restrictions. ［ C］ natural obstacles. ［ D］ fire disa