—Will you go to Tom’s birthday party tomorrow?—No，________invited to, for she is the last person I’d like to see.

Many young people don't work hard, and regret it later when the opportunity is gone.They only realize it________it is too late.

To improve the quality of our products ,we  asks  for suggestions      had  used  the products.

I was about to get on the bus ____someone called me from behind.

All the photographs in this book,     stated otherwise, date from the 1950s.