英语句子连接词：Most animals have nervous systems,sense organs,and s

因为这里的and are capable of securing,ingesting和前面的have nervous systems,sense organs,and specialized modes of locomotion共用了一个主语,是来说明主语所处的状态和特征,并不是对前面一句话的补充说明或是限定修饰
and digesting food中的and 是作为并列连词,连接的是3个动名词,就不能换成which
试着比较下以下的两个句子.
They bought two bikes,and both of them are expensive
They bought two bikes,both of which are expensive.
第一个句子是一个并列句,而第二个句子是一个含有非限定定语从句的复合句

简单点说，and specialized modes of locomotion和前面的成分如你所说是并列关系，不存在修饰关系，也不可能用which。他们都用来修饰前面的most animals

and are..不是从句，它的主语是Most animals ，两个谓语的主语相同，关系是顺接，可用and连接两个谓语，少写一次主语