Can you tell me____the train was invented?A who B when 请问选哪个?
问题描述：
Can you tell me____the train was invented?A who B when 请问选哪个?
答
when ,
如果选who 应该是 can you tell me who invented the train
答
B,指什么时候发明的
答
B什么时候火车被发明,选A的话应该有by,被谁发明.