英语高手们帮我看看这个定语从句谢谢

题目

英语高手们帮我看看这个定语从句谢谢
这是来自高中选修7的课文的一句话（有点长）
Asimov had both an extraordinary imagination that gave him the ability to explore
future words and an amazing mind with which he searched for explanations of everything,in the present and the past.
我的问题是：为什么both前面有了had ,amazing mind 后面还要有with?
我不明白什么意思.能不能举个别的例子（另一句话）也有这样的with?
或者把这句话拆开两句是怎样的?
请说明白一点.
高手们帮帮忙.非常感谢!

答案

1)这个句子的主干是：Asimov had both an extraordinary imagination and an amazing mind.
即阿西莫夫不仅有非凡的想象力,也有令人吃惊的智力.
这里had是has的过去式,both...and...相当于not only...but also.
2)that gave him the ability to explore future words这是定语从句,修饰imagination,意为他非凡的想象力可以使他探究未来的讯息.
3)with which he searched for explanations of everything,in the present and the past这也是定语从句,修饰mind,意为他令人吃惊的智力可以使他解释现在和过去所发生的一切.
这里with which是定语从句中的常用结构,例如
I have a knife with which i can peel apples.我有一把可以削苹果的刀子.
4)全句意为：阿西莫夫想象力非凡,他可以探究未来的讯息,智力也很让人吃惊,他可以解释现在和过去所发生的一切.