The days we look forward to（ ）at last.A.coming B.came C.comes D.be co

C. comes we look forward to 是定语从句，修饰the days ,且根据语境应该用一般现在时或者一般将来时，所以选C

选 B
The days we look forward to came at last.
The days we look forward to是个省略关系代词that定语从句，关系代词that 做look forward to的宾语故省略，原句是这样的：The days that we look forward to came at last.精简一下就是：The days came at last. 主语+谓语+状语，at last表过去的时间，故came用过去式。

comig
look forward to doing sth

选B。
we look forward to是The days的定语，把这个去掉的话就是The days came at last.

C.comes
we look forward to是定语从句