题干

下列关于弹力的说法中,正确的是(   )

A:相互接触的物体之间一定存在弹力作用

B:只有受弹簧作用的物体才受到弹力作用

C:只有相互接触并发生弹性形变的物体间才存在弹力作用

D:弹簧的弹力总是跟弹簧的长度成正比

上一题 下一题 0.0难度 选择题 更新时间:2017-12-12 08:03:17

答案(点此获取答案解析)

C

同类题1

  What Theresa Loe is doing proves that a large farm isn't prerequisite for a modern grow-your-own lifestyle. On a mere 1/10 of an acre in Los Angeles, Loe and her family grow, can(装罐)and preserve much of the food they consume.

        Loe is a master food preserver, gardener and canning expert. She also operates a website, where she shares her tips and recipes, with the goal of demonstrating that every has the ability to control what's on their plate.
       Loe initially went to school to become an engineer, but she quickly learned that her enthusiasm was mainly about growing and preparing her own food. “I got into cooking my own food and started growing my own herbs (香草) and foods for that fresh flavor,”she said. Engineer by day, Loe learned cooking at night school. She ultimately purchased a small piece of land with her husband and began growing their own foods.
     “I teach people how to live farm-fresh without a farm,” Loe said. Through her website Loe emphasizes that “anybody can do this anywhere.” Got an apartment with a balcony (阳台)? Plant some herbs. A window? Perfect spot for growing. Start with herbs, she recommends, because “they're very forgiving.” Just a little of the herbs “can take your regular cooking to a whole new level,” she added.“I think it's a great place to start.” “Then? Try growing something from a seed, she said, like a tomato or some tea.”
       Canning is a natural extension of the planting she does. With every planted food. Loe noted, there's a moment when it’s bursting with its absolute peak flavor. “I try and keep it in a time capsule in a canning jar,” Loe said. “Canning for me is about knowing what's in your food, knowing where it comes from.”
        In addition to being more in touch with the food she's eating, another joy comes from passing this knowledge and this desire for good food to her children: “Influencing them and telling them your opinion on not only being careful what we eat but understanding the bigger picture,” she said, “that if we don't take care of the earth, no will.”

同类题3

根据题目要求作答,紧扣题意,适当分析。

这些年,******对青年的青春寄语

十八大以来,******多次通过演讲、座谈等方式与青年频频互动,对当代中国青年寄予了殷切期望。他曾经说过:

①“人才有高下,知物由学。”梦想从学习开始,事业靠本领成就。广大青年要自觉加强学习,不断增强本领。广大青年要如饥似渴、孜孜不倦学习,既多读有字之书,也多读无字之书,注重学习人生经验和社会知识。……

②青年朋友们,人的一生只有一次青春。现在,青春是用来奋斗的;将来,青春是用来回忆的。人生之路,有坦途也有陡坡,有平川也有险滩,有直道也有弯一路。青年面临的选择很多,关键是要以正确的世界观、人生观、价值观来指导自己的选择。无数人生成功的事实表明,青年时代,选择吃苦也就选择了收获,选择奉献也就选择了高尚。青年时期多经历一点摔打、挫折、考验,有利于走好一生的路。要历练宠辱不惊的心理素质,坚定百折不挠的进取意志,保持乐观向上的精神状态,变挫折为动力,用从挫折中吸取的教训启迪人生,使人生获得升华和超越。总之,只有进行了激情奋斗的青春,只有进行了顽强拼搏的青春,只有为。人民作出了奉献的青春,才会留下充实、温暖、持久、无悔的青春回忆。……