Time flied before we knew it! It is already 12 o’clock—Oh, really? I _______ it at all.[ ]

I have so much homework to do that I don’t know ________.

Not until he received the invitation ________to attend the summit held in New York.

History is ______ a subject that lets us know something in history ,it also tells us a lot of truths.

understanding, a high school graduate hasalready reached a point in his/her life ______ he/she is supposed to makedecisions of his/her own