1. Yesterday he went off to buy a [?] car.

2. When you go to a cinema you should keep your [?] to prove that you have paid.

3. The number of cars on the road has reached [?].A solution must be found.

4. The melting of polar glaciers is among the [?] of global warming.

5. Animal and plant species could soon become [?] as large- scale agri business involves cutting down trees in rainforests.