After the trainer was sure that the whale could look after itself, he _____ it into the sea.

Jack’s mother was twenty-seven when he wasborn. Jack is eleven this year. How old is his mother?

When we worked in the same firm several years ago, we _____ often go to the cinema together.

The survey shows that a large number of teenagers are ________ cigarettes nowadays.

Who’s the little baby in the photo, Li Ying—It’s me. This photo ____fourteen years ago.