单选题
2级
2010-11-02
Why does the author call lichens pioneers?
参考答案
C
答案解析
[分析]细节题型
见第一段最后一句的伴随状语：appearing in barren rocky areas and starting the formation of soil in which mosses，then fems，and then other plants can take root(它们出现在荒芜的 多岩石地区，使得土壤开始生成，然后各种植物才得以据此生根)可知C为答案。
见第一段最后一句的伴随状语：appearing in barren rocky areas and starting the formation of soil in which mosses，then fems，and then other plants can take root(它们出现在荒芜的 多岩石地区，使得土壤开始生成，然后各种植物才得以据此生根)可知C为答案。
