题目

用图所示的实验装置研究运动和力的关系。（7分）(1)让小车从斜面上滑下后沿水平面运动，是为了使小车在竖直方向上受到的_______力和         ___________力相平衡，其作用效果相互抵消，相当于小车只受水平方向上的摩擦力。(2)每次都让小车从同一个斜面的__________位置由静止开始滑下，是为了使小车在滑到斜面底端时具有相同的_____________。(3)比较下图中小车在不同表面滑行的最大距离，可以得出：在初速度相同的条件下，水平面越光滑，小车受Grandma Moses is among the most famous twentieth-century painters of the United States, yet she did not start painting until she was in her late seventies. As she once said to herself: " I would never sit back in a rocking chair, waiting for someone to help me." No one could have had a more productive old age.She was born Anna Mary Robertson on a farm in New York State, one of five boys and five girls. At twelve she left home and was in domestic service until, at twenty--seven, she married Thomas Moses, the hired hand of one of her employers. They farmed most of their lives, first in Virginia and then in New York State, at Eagle Bridge. She had ten children, of whom five survived; her husband died in 1927.Grandma Moses painted a little as a child and made embroidery (刺绣) pictures as a hobby, but only changed to oils in old age because her hands had become too stiff to sew and she wanted to keep busy and pass the time. Her pictures were first sold at the local drugstore and at a market and were soon noticed by a businessman who bought everything she painted. Three of the pictures exhibited in the Museum of Modern Art, and in 1940 she had her first exhibition in New York. Between the 1930's and her death, she produced some 2,000 pictures: detailed and lively portrayals of the country life she had known for so long, with a wonderful sense of color and form. "I think really hard till I think of something really pretty, and then I paint it" she said.小题1:According to the passage, Grandma Moses began to paint because she wanted to_______.A．make herself beautifulB．become famousC．earn more moneyD．keep active小题2:Grandma Moses spent most of her life ________.A．nursingB．paintingC．farmingD．embroidering小题3:The underlined word “portrayals ” means ________.A. expressions       B explanations     C. descriptions  .  D. impressions小题4:From Grandma Moses' description of herself in the first paragraph, it can be inferred that she was ________.A．prettyB．nervousC．richD．independent小题5:Which of the following would be the best title for the passage?A．The Children of Grandma Moses. B．Grandma Moses: Her Life and Pictures. C．Grandma Moses: Her Best Exhibition.D．Grandma Moses and Other Older Artists.