6．听下面一段材料，回答第18至第20题．
18．How many persons were there in the room when someone was knocking at the door？
A．One person．
B．Two persons．
C．Three persons．
19．What did the young man wear？
A．A white shirt．
B．A pair of glasses．
C．Long trousers．
20．Who was the young man？
A．He was a friend of the writer's．
B．He was a friend of the writer's brother's．
C．He was a strange man to them．
鸿图图书寒假作业假期作业吉林大学出版社系列答案
B．
C．
