Question

英语高手进！！快！！重赏，一个超难的句子

英语高手进！！快！！重赏，一个超难的句子

There are occasions on which one must yield
Is this the reason for which he refused our offer?

把这两个句子还原为不是定语从句的语句，
如果可以，请详细说明什么时候用on which 什么时候用for which

Answer 1

One must yield on some occasions.
Is this why he refused our offer?

什么时候用on which和for which是根据前面的名词来定的

第一个句子是因为on some occasions
第二个句子是因为for some reasons

Answer 2

One must yield on certain occasions.
Is this why he refused our offer?
看宾语，on occasions, for...reason,都是固定搭配