the plan ------- they came up with was very good.A this B it C \ D what
问题描述：
the plan ------- they came up with was very good.A this B it C \ D what
答
C. 此题考查定语从句。the plan是先行词，而 they came up with作为定语从句修饰先行词，意为“他们想出的主意”，而关系代词that可以省略。
祝学习愉快，望采纳，谢谢！
答
C'
这是个定语从句， 所以应选关系词， A B D 都不是
选C 是因为关系代词作came up with 的宾语省略了
他们想出的这个计划很不错
【希望帮助到你，若有疑问，可以追问~~~
祝你学习进步，更上一层楼！(*^__^*)】
答
C
这是定语从句,省略了关系代词
the plan 【that/which】they came up with was very good.同时that/which 做with的宾语
翻译：他们提出的计划非常好
AB不能引导从句,D不能引导定语从句