问题补充:
When he came back from abroad, John told his parents about the cities and the people he had visited.
A. who
B. which
C. where
D. that
答案:
A. who
B. which
C. where
(答案→)D. that
解析:考查定语从句。本定语从句的先行词是the cities and the people先行词既有人又有物,使用that,在句中做visit的宾语;who只能之人; which只能指物。Where在句中做状语。故D正确。