Question

She says they found that children who drank the most soda were more than two times as likely as...

She says they found that children who drank the
most soda were more than two times as likely as those who drank no soda to show
signs of aggression.分析下句子成分，语法，as likely as 什么意思，两个as 的词性、作用一样吗？尽量说的详细明了些，谢谢！

Answer 1

这个不是地道的英语。应该是母语为非英语的人写的句子！
地道的说法应该把to show signs of aggression放到likely后面去，也许这样变换后你就清楚句子结构了。
原句的句子结构分析如下:
She: 句子主语
says: 句子谓语
they found … aggression:句子宾语(从句)，其中that children … aggression为found的宾语从句，而这其中who drink … soda是children的定语从句，were是that引导的定语从句的谓语动词，more than two times as likely to show signs of aggression as those who drink no soda是that引导的定语从句的表语，more than two times as likely to do sth as…的意思是“做某事的可能性比…的两倍还大” ，as likely as其实是形容词同级比较的表达形式(likely为形容词，意为“可能的”)。
整句译文:她说他们发现，喝苏打水最多的孩子表现出攻击性迹象的可能性是根本不喝苏打水的孩子的两倍还大。

Answer 2

She says （they found that children who drank the
主语 谓语 主语 谓语

most soda were more than two times as likely as those who drank no soda to show
signs of aggression.）

这是一个主体是宾语从句的复合句，括号里的句子是宾语从句，在这个从句中children后的从句是定语从句，而as...as..引导的是比较状语从句，是同级比较。be likely to do sth.可能做某事， two times as likely as...是指可能性相对比，是比较级的一种表达法，通常的用法是: 倍数 as adj as...