Choose the best answer.

In the United States, fossil fuels were the main source to ______ about 60% of total electricity generation in 2020.

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You may find doing this job very _______. Try it!

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Kate Bouman is ______ scientist whose algorithm allowed researchers to take _______ first ever image of a black hole.

Choose the word OPPOSITE in meaning to the underlined part.

Vietnamese have a strong sense of hospitality and feel embarrassed if they cannot show their guests full respect by preparing for their arrival.

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If a machine stops moving or working normally, you can say that it has ______ .

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The fire was so important to early cultures that scientists now study it to learn more about ancient civilizations.

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Sarah and Kathy are talking about bad habits of children

- Sarah: “Children under ten shouldn't stay up late to play computer games.”

- Kathy: “_______.”