题干

如图,盖房子时,在窗框未安装之前,木工师傅常常先在窗框上斜钉一根木条,使其不变形,这种做法的根据是(    )

A:两点之间,线段最短

B:三角形的稳定性

C:长方形的四个角都是直角

D:四边形的稳定性

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答案(点此获取答案解析)

B

同类题2

阅读理解

    Helen Thayer, one of the greatest explorers of the 20th century, loves challenges. She says, “I like to see what's on the other side of the hill.” She has gone almost everywhere to do that.

    In 1988, at the age of 50, she became the first woman to travel alone to the North Pole. She pulled her own sled (雪橇) piled with 160 pounds of supplies, and during her trip no one brought her fresh supplies. Accompanied (陪伴) only by her dog Charlie, she survived cold weather and meetings with polar bears. In fact, Charlie saved her life when one of them attacked her. Near the end of her trip, a forceful wind blew away the majority of her supplies. The last week of the trip, she survived on a handful of nuts and a little water each day.

    Helen goes to challenging places not only for adventure, but also for education. Before her Arctic journey, she started a website called Adventure Classroom. On the site, she shares her adventures in order to motivate (激发) students. She explains, “Although kids often see the world in a negative way, without hope for their future, we work to inspire them to set goals, plan for success and never give up…” Helen grew up in New Zealand. Her parents were athletes and mountain climbers. Following how parents' example, she climbed her first mountain at 9. Later, she climbed the highest mountains in North and South America, the former USSR and New Zealand.

    In 1996, she took on another challenge-the Sahara Desert. She and her husband, Bill, walked 2,400 miles across it! In 2001, she and Bill traveled on foot from west to east through the Gobi Desert in Mongolia. They hope to travel in mainland China into Sichuan and Tibet to study pandas this year.

    Helen plans to continue taking trips. She'll use her colorations, writing, photography and environmental work to create programs for her Adventure Classroom website. She wants to inspire her students never to stop facing challenges!

同类题5

任务型阅读

    Happiness is not the absence of problems____Here are a few reminders to help motivate you when you need it most:

    ⒈Pain is part of growing.

    When times are tough, remind yourself that no pain comes without a purpose____ Every great success requires some type of worthy struggle to get there. Good things take time. Everything is going to come together; maybe not immediately, but eventually.

    ⒉____

    Every time it rains, it stops raining. Every time you get hurt, you heal. After darkness there is always light. So if things are good right now, enjoy it. It won't last forever. If things are bad, don't worry because it won't last forever either.

    ⒊Worrying and complaining changes nothing.

    ____ It's always better to attempt to do something great and fail than to attempt to do nothing and succeed. It's not over if you've lost; it's over when you do nothing but complain about it. If you believe in something, keep trying. Don't let the shadows of the past darken the doorstep of your future.

    ⒋Your scars are symbols of your strength.

    Never be ashamed of the scars life has left you with. A scar means the hurt is over and the wound is closed. It means you overcame the pain, learned a lesson, grew stronger, and moved forward____

A. Everything in life is temporary (暂时的).

B. But it is the ability to deal with them.

C. Rarely do people do things because of you.

D. A scar is the sign of a success to be proud of.

E. Those who complain the most, accomplish the least.

F. Move on from what hurt you, but never forget what it taught you.

G. Change because it makes you a better person and leads you to a brighter future.