题干

已知:如图,在平行四边形ABCD中,E,F分别是AB,DC上的两点,且AE=CF.求证:BD,EF互相平分.


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证明:∵平行四边形ABCD>∴AB=CD>∵AE=CF>∴DF=BE>∴四边形EBFD是平行四边形>∴BD,EF互相平分

同类题2

阅读下列短文,从每题所给的A、B、C和D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。

C

    How often do you check your phone? According to a study led by Nottingham Trent University in Britain, the average person looks at their phones 86 times a day. Updating their status on social media platforms also made people reach for their electronic companion frequently.

    Even the participants thought that was a lot: this figure is twice as often as they thought they did. Our phones might be shaping our behavior more than we realize. Do you actually look at your surroundings more than at your phone? Is it rude to check your phone when someone is talking to you?

    Sherry Turkle interviewed hundreds of college students about this. She's a professor of social studies at the Massachusetts Institute of Technology. They talked about something they called "the rule of three".

    The rule has to do with being considerate to others despite the allure (诱惑力) of the little flat box. Turkle explains: "If you go to dinner with friends, you don't want to look down at your phone until you see that three people are looking up in the conversation. So there's a new rule where you don't look down unless three people are looking up in order to keep a little conversation alive."

    Actually, if you are clever enough you might use your phone as a tool to connect with people next to you. Sharing a bit of your life with them can bring you closer together. And you can also invite everyone to take a selfie (自拍照) with you.

    But the best thing to deal with mobile phone addiction is to go cold turkey and leave the machine behind occasionally or just switch it off and keep it firmly in your pocket for a while.

同类题3

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    Travelling around the world with children is difficult enough, while attempting it without using motorized transport is even more of challenge.Even so, Dario Schworer a 42-year-old climatologist and mountain guide, and his 33-year-old wife Sabine are on a journey to do just that.

    The Swiss couple want to travel across the world's oceans and climb the highest mountain on every continent to promote Earth-friendly ways of life.

    "We are collecting good examples of dealing with climate change and living in harmony with nature and we want to spread such ideas." Schworer said."We want to help people affected by global warming and to inspire children for the future."

    Recently after having spent three months teaching children in the Everest region, the couple want to show it is possible to travel through the world's climate zones using just human-power and forces of nature.

    In the 47 countries they have visited they have collected 22 tons of trash, taught people in Ecuador how the sun's rays can be used to clean water and inspired a person in Chile to build a house on water with recycled plastic bottles as a foundation.They have also collected trash in the mountains of Nepal with school children.

    So far they have communicated with 45,000 children from South America, Australia and Asia, giving presentations about the importance of recycling and using alternative energy like solar and wind power.

    When they began their adventure in 2003 they had no children of their own.But since then two has become five: daughter Sabine is now five years old, Andri was born in Chile and baby Neo was born in Australia.

    Initially the couple thought they would complete their travels in four years, but now, they believe it could take seven more.

    "Since our belief is the need to respect nature, we travel only when conditions are good," Schworer said.