_________ is known to all，good friends _________ happiness and value to life.

Two students in our school will go to the beach.

I have a lot of homework to do today, _________ I cannot go swimming with you.

Jack is a famous writer. ＿＿＿new book is very popular.

You look so happy. What happened?—I have just got an “A” in P.E. test.