. When we think of communication, we ____ think of using words, talking face to face, writing messages, and so on.
With the help of high technology, many new substances(物质)______in the past years.
______ is know to us all, good friends ______ happiness and value to our life.
Letterboxes are much more _______ in the UK than in the US, where most people have a mailbox instead.
I’m certain David’s told you his business trouble. ________, it’s no secret that he owes a lot of money to the bank..
---- Will Joe attend the party? ----- If his wife won’t go to the party,_________.