433. Last but not the least reason is that human activity could make animals and plants extinct.
最后但并非最不重要的一个原因就是人类活动使得许多动植物灭绝。

六级词汇讲解:
本句用于论证中最后一个理由或观点的引出。last but not the least reason意思是“最后一个但并非最不重要的一个原因”。在书面用语中，也多用last but not least引出最后一个分支观点。

句型拓展:
The final reason I think movies are so popular is the movie stars.
最后，我认为电影如此受欢迎的一个原因是因为有电影明星。
Last and importantly, the way the stories are presented reveals the level of technology in that country.
最后但很重要的一点是，故事情节的讲述方式能反映一国的技术水平。
Most of all, it's easy to remember special gifts because they give you a feeling of self-worth.
特别的礼物之所以令人难忘，最重要的原因是它会让你感受到自身的价值。
Last of all, a home-based school system will help our society achieve equality in education.
最后，家庭教育体制有助于实现全社会的教育机会均等。