汽车等速行驶时，主要存在哪些阻力？它们各是怎样产生的？ 发布时间：2020-01-05 01:33 │ 来源：www.tikuol.com 题型：问答题 简答题 问题： 汽车等速行驶时，主要存在哪些阻力？它们各是怎样产生的？
题型：问答题 简答题 短文改错。 Three young pioneers were playing while they saw a young tree bending to one side with some of it's leaves falling. They felt sadness and decided to save it. They put up a hard stick close by and tie the tree to it to make it straightly. Then they make a fence around it to prevent people and animals of coming near. They also put up a board there, on that they wrote:"Cherish young tree." After that, the three often came to watering the tree. Gradually, the young tree grew straight and strong. Their teacher learned this and praised them, "Well do. Children." 1.________ 2.________ 3.________ 4.________ 5.________ 6.________ 7.________ 8.________ 9.________ 10.________ 查看答案