The two generations, It is often not their age, （ ） their education that causes misunder standing.

单项选择题---Have you found the information about famous people （ ） you can use for the report---Not yet,I’11 search some on the Internet.

单项选择题---It’s a long time since I saw my sister. ----（ ）

单项选择题It （ ） be Mike. I saw him go to the library just now.

单项选择题---Sir,could you please put out your cigarette This is a smoke--free(无烟的)school.---（ ）

单项选择题If only I （ ） that was the last chance I could talk to her.I would have said to her,“Hi,my dearest mom! I love you”.