二、判断（每题2分，共10分） 1. 新车和大修车的机械传动效率是最高的。（） 2. 发动机点火正时灯可用于离合器打滑的检测。（） 3. 前束可引起正侧滑；车轮外倾可引起负前束。（） 4. 转向轮外倾和前束均匹配情况理想时,侧滑量不为零。（） 5. 推力角并非设计参数,而是一种故障状态参数。（）

A、三阶

B、二阶

C、一阶

D、五阶

A、利用在物理场改变时溶解度下降、发生可逆性沉淀的水溶性聚合物为载体固定亲和配基，制备亲和沉淀介质

B、亲和介质结合目标分子后，通过改变物理场使介质与目标分子共同沉淀的方法成为二次作用亲和沉淀

C、进行亲和沉淀后，离心或过滤回收沉淀，即可除去未沉淀的杂蛋白

D、沉淀经适当清洗后加入洗脱剂即可回收纯化的目标产物

A、同步二进制计数器

B、异步二进制计数器

C、加法计数器

D、减法计数器

简述二苯胺法鉴定DNA的原理是什么？

请写出下面方程的二次守恒格式？

设其中具有二阶导数，求

二次积分交换积分次序可化为

此二端口网络的Z参数：Z11=（ ）Ω。

此二端口网络的Z参数：Z21=（ ）Ω。

翻译练习（二） Instant Expert: Robots Ever since the Czech writer Karel Capek first coined the term “robot” in 1921, there has been an expectation that robots would someday deliver us from the drudgery of hard work. The word — from the Czech “robota”, for hard labour and servitude—described intelligent machines used as slaves in his play R. U. R. (Rossum’s Universal Robots). Today, over one million household robots, and a further 1.1 million industrial robots are operating worldwide. Robots are used to perform tasks that require great levels of precision or are simply repetitive and boring. Many also do jobs that are hazardous to people, such as exploring shipwrecks, helping out after disasters, studying other planets and defusing bombs or mines. Robots are increasingly marching into our lives. In the future, robots will act as our carers, medics, bionic enhancements, companions, entertainers, security guards, traffic police and even soldiers. A recent report published by the United Nations revealed that sales of domestic robots had tripled in a single year. What’s more, they were well on their way to outstripping their industrial cousins. While a large portion of the household robots were made up of robotic vacuum cleaners, mops, lawn mowers, pool cleaners, security bots and even robotic baby-rockers, the real boom was in entertainment robots. Suddenly people were happy to pay for robots that had no specific functional value. Instead these bots, such as Sony’s Aibo robotic dog and its robo-pups served as robo-pets and companions, rather than slaves.