1、Perseverance is a kind of quality ----and that is ______ it takes to do anything well.

A what B that C which D why

答案是：A 请问为什么？请告知B、C、D 各自的用法，并翻译句子的意思。不胜感激。

2、____ matters most in learning English is enough practice.

A what B why C where D which

答案是：b 请问为什么不选其他的？ 请翻译句子的意思。不胜感激。

1、Perseverance is a kind of quality ----and that is ______ it takes to do anything well.
A what B that C which D why

A
定语从句中what=the thing that，你代进去通顺就可以了。
Perseverance is a kind of quality ----and that is the thing that it takes to do anything well.

it takes some time to do sth.这个句型你肯定很熟悉吧？take是及物动词，所以这里肯定是用what，不然缺成分。
BC肯定不能选，先行词都没有，何来关系代词?why代进入也缺成分。
BCD都是常用单词，各自的用法我讲不清楚，你可以去百度上搜索。这句话的大致意思是：坚定是事业成功的保证。

2、____ matters most in learning English is enough practice.
A what B why C where D which
答案是：b

我认为选A，还是那样，what=the thing that
The thing that matters most in learning English is enough practice.
学英语最关键的是要有足够的练习/训练。