How happy we are! The holiday we have been looking forward _______ at last.
A. to has come B. to have come
C. to having come D. has come
How happy we are! The holiday we have been looking forward _______ at last.
A. to has come B. to have come
C. to having come D. has come
A
the holiday为句子主语，we have been looking forward to 是修饰主语的定语从句(介词 to 的宾语是引导该定语从句的关系代词 that，被省略)，has come 是句子谓语。