第21题: [单项选择]What conditions are needed lot shrubs to become established A. Ferns must take root. B. The ground must be covered with grass. C. More soil must accumulate. D. Smaller plants must die out. 参考答案:C 答案解析:[参考译文]灌木稳固生长需要什么条件
[试题分析]同上。
[解答要领]在第三段的中间,只有在长过苔藓之后草木和shrub(灌木)才能生长,因为已经固定相当一部分土壤,有利于植物生长,故选C。
A. does not exceed that of programs B. is greater than that of programs C. varies over a large range than that of programs D. is less than that of programs 参考答案:A 答案解析:[解析] 事实细节题。根据第一段第四句(According to one NBC executive,no difference exists in the peak sound level of a
第26题: [单项选择]2008年该省通过铁路运输货物的平均运距约为( )公里。 A. 172.65 B. 690.6 C. 539.8 D. 324.2 参考答案:B 答案解析:[解析] 2008年该省铁路运输的货物周转量为:323.9÷(1-6.2%)≈345.3(亿吨公里)。铁路运输货运量为:6137.4÷(1+19.9%)≈5118.8(万吨)=0.5(亿吨)。又因为货