我觉得这里不需要would have, would本身就够了，大家觉得呢？

小黛安

For many people, household labor remains demanding even if able to afford household appliances their grandparents would find a miracle.

even if able to afford household appliances their grandparents would find a miracle
despite being able to afford household appliances their grandparents would find a miracle
even if they can afford household appliances their grandparents would have found miraculous
although they could afford household appliances their grandparents would find miraculous
even if they are able to afford household appliances which would have been a miracle to their grandparents

SEAS

我也是这么想的，不需要would have，高中里老师教的时候would have done 的意思是本应要做但没有做，很神奇，所以现在就不懂了~~

清飞扬

正确答案就是正确的，不要去费时间纠结。还是把时间放在如何选对的思路上吧

aeoluseros

would find和would have found的意思是不一样的。
前者表示他们的父母现在或者将来可能觉得神奇（对现在或将来的假设、虚拟），后者表示他们的父母在过去时会觉得很神奇的仪器(对过去的假设、虚拟)。
比如吸尘器，如果是放到我外婆年轻的时候（如60年前），她会觉得是非常miraculous的东西。但是现在我外婆看来已经不算什么稀奇事物了。
正确答案应该是C
翻译一下：对于很多人来说，家务劳动依然很费力，即使他们能买得起那些他们的祖父母过去觉得不可思议的家务电器。
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D选项除了would find把原意改了，还有两个小错误：
1. although前面需要用逗号.
2. although已经表示了明确的对比，所以用can比用委婉的could好。