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
A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。