---How long do you think it will be _____China becomes a developed country?---At least 20 years, I guess.
You must know why she got angry this morning,_________.
—Thank you for helping me order the food. —_________.
They _____the battle but lost many men.
. It’s quite an informal gathering ; you needn’t ______for it .
I’m surprised that you should have been fooled by such a(an) ____trick.