Put in a/an or nothing(-) Помогите пжл1. Teenagers like to listen

Put in a/an or nothing(-) Помогите пжл
1. Teenagers like to listen to _ music.
2. Could I have _ glass of _ water?
3. _ Trafalgar square is the most famous square in London
4. Niagara Falls are the most powerful waterfalls in_ North America
5. _ Simpson Desert is situated in the center of Australia
6. They sey _ exotic animals were first taken to Britain in the 13 centery.
7. _ tea is Britain's favorite drink
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