[解析]
(1)C 细节题.根据第一段no animals could have been living if plants hadn't been on land first.可知没有植物,动物根本不能存在,故选C.
(2)A 细节题.第一段说陆地上的生命出现于430 million years ago,第二段说海藻是最早的植物.故选A.
(3)C 细节题.根据文章第一段Life on land probably began about 430 million years ago,thought it had existed in the water for perhaps as long as 3,000 million years.最早出现的植物在四亿三千万年前,一亿年后植物开始生根,即三亿三千万年前.故选C.