1961年，中共中央农村工作部的一份报告指出：现在部分干部和农民对集体生产信心不足，以致发展到变相恢复单干，有的地方出现了“父子队”“兄弟队”式家庭作业。材料所反映的历史现象（ ）
The teacher stood before his class of 30 students and was going to hand out the final exam papers. “I know how hard you have all worked to get ready for this test. he said. “And because I know you are all able to understand these questions. I am ready to offer a B to anyone who would prefer not to take the test." A number of students jumped up to thank the teacher and left the classroom. The teacher looked at the rest students and said. “Does anyone else want to get a B? This is your last chance. ”Two more students decided to go. Seven students stayed. The teacher then handed out the papers. There were only three sentences on the paper： Congratulations! You have received an A in this class. Keep believing in yourself. I never had a teacher who gave a test like that. but I think that it is a test that any teacher could and should give. Students who do not have confidence in what they have learned are B students at most. The same is true for students in real life. The A students are those who believe in what they are doing because they have learned from both successes and failures. They have learned life’s lessons. whether from school education or from events in their lives，and have become better people. Scientists say that by the age of eight，80% of what we believe about ourselves has already been formed. You are a big kid now and you realize that you have some limits(局限). However, there is nothing you can't do or leant to be. Sir Edmund Hillary, the first person to reach the top of Mount Qomolangma (珠穆朗玛峰)said，“We do not conquer the mountain, but ourselves. ”
我国志愿者王跃曾与俄罗斯志愿者一起进行“火星﹣500”的实验活动．假设王跃登陆火星后，测得火星的半径是地球半径的 12 ，质量是地球质量的 18 ．已知地球表面的重力加速度是g，地球的半径为R，忽略火星以及地球自转的影响，求：
吟诗弄词
①小明是个顽皮的孩子，五年级的学生还不知道学习的重要性，成天心思不在学习上，请你用学过的诗句劝他：____，____。
②有时候，有些人对自己所处的环境下正在做的事情反而不及旁人看得清楚，这就是人们常说的：“ ____，旁观者清。” ____ 朝诗人 ____在《____》中的诗句“____，____。”说明的就是这个朴素的道理。
③和平阳光普照下的我们，要牢记历史，珍惜今天：风声雨声读书声，____；____，____。因为“天下兴亡，____。
