请英语能手帮忙一下

that指代与上文中相同的内容，此句中指system，当指代上文中的内容为可数名词复数时用those。另外此句中that是from中的介宾，而which一般用于定语从句中，要有先行词，这里没有先行词，不是定从，成份不对，所以也就不能用which。

肯定是that啊

which 后面怎么能没动词呢？难的形式主语后面直接接at home?

those也不对，因为句子提到的是a highly system 是单数

还有啊，怀疑是higly吗？起码应该highly performed吧

一.that仅用在限制性定语从句中，通常不用逗号隔开，作宾语或介词宾语时，that 可以省去。例：
The letter that came this morning is from my father.
今晨收到的那封信是我父亲寄来的。
The watch(that)you gave me keeps perfect time.
你给我的那块手表走得准极了。
The photographs(that) you're looking at were taken by my brother.
你正看的这些相片是我弟弟照的。

二.which既可用在限制性定语从句中，作宾语或介词宾语时，which可以省去，也可用在非限制性定语从句中。例：
Did you see the letter that/which came today?
今天来的信你看到了没有？
This is the one of which I'm speaking./This is the one I'm speaking of.
这就是我说的那一个。
He changed his mind, which made me angry.
他改变了主意，使我很生气。
He admires Mrs.Brown, which surprises me.
他钦佩布郎太太，这使我感到惊奇。

三.当先行词是不定代词或