问题
选择题
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
答案
答案：A
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。