They were visited by a large colony of ants which obtained asort of honey from them. I immediately embarked on an experiment which, eventhough it failed to get rid of the ants, kept me fascinated for twenty-four hours. Ibound the base of the tree with sticky tape, making it impossible for the ants to reachthe aphids.

　　19.They were visited by a large colony of ants which obtained a sort of honey fromthem.

　　蚜虫遭到一窝蚂蚁的攻击，蚂蚁从它们身上可以获得一种蜜。

　　语言点:句子结构分析:were visited by在本句中是含蓄陈述修辞格，直译过来就是“蚜虫收到蚂蚁的拜访”，但是这样讲肯定会让人觉得好笑，因此采取意译。

　　20.I immediately embarked on an experiment which, even though it failed to get ridof the ants, kept me fascinated for twenty-four hours.

　　我当即动手作了一项试验，这项试验尽管没有使我摆脱这些蚂蚁，却使我着迷了24小时。

　　语言点:embark on an experiment的意思是“着手做一项实验。”

　　21.I bound the base of the tree with sticky tape, making it impossible for the ants toreach the aphids.

　　我用一条胶带把桃树底部包上，不让蚂蚁接近蚜虫。

　　语言点:句子结构分析:现在分词短语making it impossible...作结果状语。