题目

测速仪器用超声波测汽车速度，第一次发出的超声波经过0.4秒接收到返回的超声波，与第一次间隔1秒再发出第二次超声波，经过0.3秒接收到返回的超声波，声速340米/秒，若汽车做匀速直线运动。则汽车在接收到这两个超声波信号之间的时间里行驶的距离是______m，汽车行驶的速度是______m/s（保留一位小数）。根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。Today our life and work rarely feel light or pleasant. Instead, the whole experience of being alive begins to melt into one enormous obligation(责任). 【1】We say this to one another with great pride. 【2】 We are unavailable to our friends and family, unable to find time for the sunset, to finish off our obligations without time for a single mindful breath. This seems to have become the model of a successful life.Because we do not rest, we lose our way. We lose the relaxation that gives us help. 【3】 Poisoned by the belief that good things come only through tireless effort, we never truly rest. This is not the world we dreamed of when we were young. But how did we get so terribly rushed in a world filled with work and responsibility, yet it lacks joy and delight?【4】 Sunday is the time to enjoy and celebrate what is beautiful and good, time to sing songs, give thanks, and walk. It is time to be refreshed as we stop our work, our chores and our important projects.Sunday is more than the absence of work. Many of us, in our desperate drive to be successful and care for our many responsibilities, feel terrible guilty when we take time to rest. 【5】 Many of us still recall when, not long ago, shops and offices were closed on Sundays. Those quiet Sunday afternoons are deep in our cultural memory.A. We also miss the quiet that gives us wisdom.B. All work and no play make Jack a dull boy.C. It becomes the standard greeting everywhere, “I am so busy.”D. We work through day and night, feeling rather exhausted.E. But the Sunday has proven its wisdom over the ages.F. The reason is simple: we have forgotten the Sunday.G. The busier we are, the more important we seem to ourselves and, we imagine, to others.