各位高手帮我出20道英语的单项选择题！

1.This is ___B________ empty bottle. Could you give me __________ full one?

A. a, a B. an, a C. the, the D. /, a

2.It's too hot today. Please give ______C_____ a bottle of orange.

A. mine B. he C. her D. our

3. _____A______ our football team failed in the match, we did our best.

A. Though B. But C. Because D. As

4. Xi'an is one of _____D______ capital ___________ in China.

A. older, city B. the older, city

C. oldest, cities D. the oldest, cities

5. The river is very long and it is about _____A______.

A. 20 metres wide B. 15 metres long

C. 30 metres high D. 50 metres tall

6. ----- ______A_____ a year does your school have sports meeti