第1题: [单项选择]What conditions are needed for 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)。