A                             is a tube through which a person swimming just under the surface of the sea can breathe.

Scientists warn that many of the world’s great cities are                                                                                           flooding.

The world’s biodiversity is declining at an unprecedented rate, which makes wildlife              .

Silence                                        the theatre as the audience awaited the opening curtain with expectation and excitement.

When the kids asked him about his girlfriend, he’d go as red as a                  .

I am sure your sister will lend you a sympathetic                                                                                 when you explain the situation to her.

Many young people in rural areas don`t want to spend their lives on the farm like           parents.

The trouble with James is that he never                                                                                      on time for a meeting.