阅读，回答下列问题。    

     车子上运着两只桶，一只盛着酒，另一只空无所有。前者一路上沉静地没有发出一点儿声音。后者跳跳蹦蹦，闹得一路上回声震耳，尘土像云雾似的飞扬，焦急的行人老远就听到吵闹的声音，诚惶诚恐地躲在一边。然而不管后者怎样地哗众取宠，像前者那样的价值，它却没有。

交通工具的发明和进步改变了人类的生活。世界上最早的火车和飞机的发明者分别(      )

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Researchers have discovered the first Earth-sized planet. It was first marked by NASA's Kepler telescope(望远镜) so it's called Kepler-186f. It lies about 500 light years from Earth and goes around its star. The planet is the right distance from its star for water: not too close or not too far. Water is one important condition that scientists guess is necessary for life. So it could have water and possible life. It's called a true Earth cousin.

"This planet is an Earth cousin, not an Earth twin," said Barclay, who is among a team of scientists reporting on the discovery in the magazine Science this week.

"It's very exciting to find a planet similar to the Earth," Barclay said, "It's not easy work because things change as we get more measurements."

Scientists don't know anything about the air of Kepler-186f, but it will be a task for future telescopes which can study for chemicals that have something to do with life.

    "It's possible for life to live in this planet, but that doesn't mean there is life in it," Barclay said.

So far, scientists have found nearly 1,800 planets in the universe.

"The past year has seen a lot of progress in the search for Earth-like planets. Kepler-186f is very important because it is the first planet that is the same temperature and is almost the same size as Earth," scientist David Charbonneau wrote in an email.

卧室内有一盏照明灯，门口、床头各有一只单刀双掷开关，这两只开关都能控制照明灯，请在图中将这个电路画完整．