请教一个句子的句子结构，该如何断句，谢谢！！

babies enter the world with the ability {(to make precisely thoese perceptual discriminations) that are necessary (if they are to acquire aural language.)} 【 在 Exciting (喜剧之谜) 的大作中提到: 】 : babies enter the world with the ability to make precisely those perceptual discriminations that are necessary if they are to acquire aural language。

句子的主干是babies enter the world with the ability？谢谢!! 【 在 Farrell 的大作中提到: 】 : babies enter the world with the ability {(to make precisely thoese perceptual discriminations) that are necessary (if th iPhone客户端1.3发布

嗯，是的。你可以理解成：babies enter the world with the ability to make those perceptual discriminations precisely. Those discrimination are necessary if they are to acquire aural language.为了把两句说成一句变成那种结构的

【 在 Exciting 的大作中提到: 】 : babies enter the world with the ability to make precisely those perceptual discriminations that are necessary if they are to acquire aural language。 句子的主干应该是 babies enter the world to make precisely those perceptual discriminations吧 其他不是定语从句 that are necessary 就是状语with the ability 还有状语从句if they are to acquire aural language

谢谢！ iPhone客户端1.3发布

【 在 Exciting 的大作中提到: 】 : 句子的主干是babies enter the world with the ability？谢谢!! : iPhone客户端1.3发布 其实主干就是babies（主） enter（谓） the world（宾）