Choose the best answer among A, B, C or D.

- A: Where is your sister? - B: She is busy_________ dinner in the kitchen.

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Human beings have a great influence on the rest of the world.

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Oil, coal, and natural gas are_________.

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Water is one of the most important resources _________for our life.

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I was talking to a man _________has worked with my father since last week.

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The old man _________a green suit is a famous energy researcher.

Choose the best answer among A, B, C or D.

The Asian Games have been advancing ______all aspects.