Find the mistake.

In the cities of the future, most vehicles will power by renewable energy.

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Scientists are trying to make home electric gadgets more ______.

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Joe has some solar panels on his house rooftop. He ______ save some electricity from today.

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Drone ______ will be faster and cheaper for customers.

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______ there will be more green trees than buildings in future cities.

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Different kinds of 3D printers ______ build houses more quickly and cheaply in the next 50 years.

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In future homes, energy use ______ automatically.