— Have you been to the Great Wall?
—Perhaps not in my memory. ________, it might have been during my early childhood.

I would appreciate         back this afternoon.

Attention！_______ in the form right now，making sure that every detail supplied is accurate.

His explanation was so clear that everyone could understand it with ________.

Into the flat _______，who was quite excited when everyone shouted“Happy New Year"．

I’m not a little tired today after giving the room a thorough cleaning and I have never had_________today.

“Well done, John.！ Not a single mistake _____ in your exam paper this time！”said the teacher.

To help a friend solve the problem troubling him,     .

Not until all the fish died in the river      how specious the pollution was.

---It’s getting dark, but Mr. Johnson is still at his office.
---No surprise. Who else can ______ he does?