同学你好，该知识点来自沪江网校《2020考研公共课名师联报班 政治+英语一【天猫专享】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

who引导定语从句
that引导宾语从句
To those, [状语] animal research [主语] seems [系动词] wasteful [表语] at best [状语] and [连接词] cruel [表语] at worst. [状语]
Those [主语] are unaware [谓语] something. [宾语]
Animal research [主语] was needed [谓语] to produce these treatments, [主语补足语] as well as [连接词] new treatments and vaccines. [主语补足语]
许多人都不了解，要想获得这些新的治疗方法和疫苗，就必须进行动物实验，对于他们来说，动物实验说的好是浪费，说不好是残忍。