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
【分析】其实正确答案是A。大家知道，短语 look forward to意为“盼望”，其中的 to 是介词，而不是不定式符号，所以后接动词要用动名词，许多同学据此便选择了C。但问题是，句中介词 to 的宾语不是have come，而是the holiday。正解的句子分析是：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。
■The man you referred to _____ just now.
A. comes B. come
C. coming D. came
【分析】答案选 D，句子主语为 the man，you referred to 为修饰 the man 的定语从句，空白处填 came，为句子谓语。
■The theory he sticks to ______ to be of no use in our studies.
A. proves B. prove
C. proving D. be proved
【分析】答案选 A，he sticks to 是修饰主语 the theory 的定语从句，句子的基本结构为 The theory proves to be of no use in our studies.
■The work he devoted his time to _____ worth praising.
A. was B. be
C. being D. been
【分析】答案选 A，he devoted his time to 是修饰主语 the work 的定语从句。句子的基本结构为 The work was worth praising.
■I think this is the very work that we must finish ____ her.
A. to help B. help
C. helping D. helped
【分析】答案是 A。句中空格处填的动词help 并不是 finish 的宾语，正确的句子分析是：that I must finish 是修饰名词 the very work 的定语从句，finish 的宾语是引导该定语从句的关系代词 that，其后的不定式 to help her 是目的状语。
■Which do you enjoy ____ your weekend, swimming or fishing?
A. spending B. being spent
C. spend D. to spend
【分析】答案选 D。enjoy 的宾语是句首的疑问词 which，不是其后的动词 spending。此题中的 to spend… 用作目的状语。