问题补充：
－He asked Tom, “Have you finished your homework？”
－He asked Tom.
A. if had he finished his homework.
B. whether he had finished his homework
C. if he had finished your homework.
D. if you had finished your homework.
答案：
A. if had he finished his homework.
(答案→)B. whether he had finished his homework
C. if he had finished your homework.
D. if you had finished your homework.
解析：连词辨析。If和weather都能表示是否的意思，但是if还可以引导条件从句，表示如果。当可能引起歧义时就只能用weather了。宾语从句中一般为陈述语序，可排除AD选项。选项C还可以表达，如果他完成了作业，他问汤姆的意思。故选B最符合上文语义。
