题型:填空题 请先阅读下面短文,用其适当形式填空白,每个词限用一次。so start easy badly someone difficult if thank class reporter medical succeed I' m John Wood, a doctor at a famous Boston hospital. During the first two years of high school, I found biology very 1 . My report cards always said things like "must study harder" or "John shouldn't choose science 2 ." It was really terrible for 3 who had always dreamed of becoming a doctor. I lost confidence, so I left high school x j at sixteen and 4 working at a supermarket. One evening I saw a documentary about Albert Einstein. According to the documentary, Einstein had done really 5 at school. I began to think that Einstein could 6 , then I may have a chance, too. I didn't want to leave my job, 7 I decided to go to night school to finish high school. Two years later, I went to a 8 university. I've often thought I should contact the 9 the Einstein documentary and 10 him. As for the biology teacher, I might contact her, too, one day - but not to thank her! 1____________ 2___________ 3_________4____________ 5____________6_____________7____________ 8__________9____________ 10_____________ 查看答案
题型:选择题 下列关于速度和加速度的说法中,正确的是( )A.物体的速度越大,加速度也越大B.物体的速度为零时,加速度也为零C.物体的加速度方向为正方向时,物体一定做加速运动D.物体的加速度在增大,速度可能在减小 查看答案
题型:问答题 在今年的“劣质奶粉事件”中,一些无辜幼童身受其害,变成“大头娃娃”,甚至死亡,原因是这些奶粉中蛋白质含量过低.蛋白质是生命的物质基础,其降解的最终产物是氨基酸.其中精氨酸是儿童生长必需的一种氨基酸,它的化学式为C6H14O2N4.(1)精氨酸由______种元素组成.(2)在精氨酸中,氢、氧两元素的质量比为______(最简整数比). 查看答案
题型:填空题 已知有机物 A、B、C、D、E、F之间的转化关系如图所示。D 是常用做汽车发动机的抗冻剂,E为聚合物,F的式量为26。根据信息回答下列问题。(1) 写出A中官能团名称 (2) B转化为C的反应类型 (3) 有机物D具有以下哪几方面的化学性质: (填序号)① 加成反应 ②取代反应 ③消去反应 ④氧化反应 ⑤ 还原反应(4) E的结构简式为 (5) C—F反应的方程式 查看答案