Animals that could not adapt themselves to the environment perished and those that could survived
问题描述：
Animals that could not adapt themselves to the environment perished and those that could survived
其中that could survived 中的 that 那么理解 为什么这么用
为什么 用 those又用that
答
两个that引导的是定语从句,引导词分别是animals和those,两个引导词在从句中都是主语,句子构成是这样的：
Animals (that could not adapt themselves to the environment) perished and those (that could)survived.
第一个括号里是animals的定语,意思是：（那些不能适应环境的）动物；
第二个括号完整的应该是that could adapt themselves to the environment,是those（代指animals）的定语,意思是：（那些能适应环境的）动物；
整句话直译的话是“不能适应环境的物种遭到灭绝,能适应环境的得以存活.”
其实就是“物竞天择,适者生存”的意思.