On a rainy day I was driving north through Vermont, I noticed a young man holding up a sign “Boston”.
A. where; reading
B. when; reading
C. where; to read
D. when; to read
网友回答
(答案→)A. where; reading
B. when; reading
C. where; to read
D. when; to read
解析：考查定语从句的同时考查非谓语动词的用法。where引导的非限定性定语从句修饰Vermont，现在分词reading表示主动，说明sign的内容。