什么是机车两系弹簧点头振动？怎样克服？

There are warm tropical regions all over the globe, but only the Indians of the South American rain forests have formed the habit of sleeping in the open air. Long before they made painful acquaintance (相识) with Europeans, they had invented something that was unique on earth: the hammock.

Nobody really knows who first had the bright idea of making sleeping in the air the symbol of untroubled rest. The Indians see the hammock as a “gift of heaven (上天)”, something given to them a very long time ago.

In it the Indians pass away hot noon hours, napping or chatting. Swinging it to and fro (来回摆动) creates a cooling breath of air and keeps away insects. They work and play in hammocks, are born and die there.

Hung like a suspension bridge between heaven and earth, a hammock is dry while the soil is damp and is safe from most wild animals.

Hammocks have the advantage over beds in that they are easy to transport and take up very little space when they have been rolled up(卷起) . Indians never go on a journey without their hammocks, not even to their plantations.

76.The word hammock in this passage means _______.

A. a suspension cage which can be swung to and fro in the air

B. a seat hanging by two ropes from the branch of a tree

C. a suspension bridge in the South American rain forests.

D. a net hung between two supports and used as a bed.

77. When was the hammock invented and by whom?

A. The Indians had invented the hammock long before they came to South America.

B. The Indians had invented the hammock long before the Europeans came to South America.

C. The Europeans invented the hammock after they made acquaintance with the Indians.

D. The Europeans had invented the hammock before they went to South America.

78. Indians swing the hammock to_______.

A. pray to heaven for a gift       B. keep away flies, mosquitoes and other insects

C. keep away wild animals        D. all asleep quickly

79. According to the passage, hammocks _______.

A. cannot be rolled up                B. are difficult to transport

C. are never brought to the plantations   D. can be kept dry while the ground is wet

80. The passage is about _______.

A. the Indian way of living                      B. tropical regions

C. Indians' gift for the Europeans           D. a portable bed

在一个小型会议室里某公司正在对前来应聘的大学生进行面试。以下是毕业生小李与主考官的对话实录：小李：各位领导、老师好！主考官：请坐！介绍一下自己，好吗？小李：非常高兴你们到我们学校来招聘毕业生，我叫李华，是本校计算机系的应届毕业生。我对软件开发很有兴趣，在这方面投入了不少精力；同时作为班团干部也参与、组织了不少社会活动，应该说大学期间我在这两个方面都有不少的收获。这是我的成绩单和个人简历，请你过目。主考官：你了解我们公司吗？小李：贵公司是国内著名的电讯公司，我从上大学起就十分向往毕业后到贵公司工作。我认为到贵公司工作能最大限度地展示我的才华，我不怕吃苦，就怕无事可做。主考官：上大学时你为什么报考计算机专业？小李：说实话当时报考计算机专业是老师和家长的主意。但我在学习了计算机方面的知识后就深深的爱上了我的专业。特别是随着信息时代的到来，我对自己的专业发展前景非常有信心。主考官：你学过的课程与我们的工作有什么关系？小李：我想，计算机技术的广泛采用是电讯业的特点和发展趋势。我们计算机专业的课程设置几乎涵盖了硬件和软件技术的主要方面，这为我们打下坚实的理论基础，同时也使我们有较强的适应能力，前面我已说过对软件开发更有兴趣，我想这方面的知识和能力也许是将来的工作需要的。主考官：你喜欢你们的学校吗？你们系的老师怎样小李：我非常喜爱我的母校，我也非常尊敬我的老师，因为我在母校学到了知识，我从老师身上学会了做人。主考官：你还有哪些特长和爱好？小李：除了专业外我还具有一定的组织管理能力，喜欢美术和流行音乐，也喜欢背起行囊去游历名山大川。主考官：你有哪些缺点？小李：我得承认我还缺乏实际工作经验，这方面得不足还需要在今后的工作实践中不断学习和弥补。再就是外语学得不够好，还需继续努力学习。主考官：你对加班、出差怎么看？小李：我近几年内不会考虑结婚，没有家庭负担和拖累，加班应该没有问题。至于出差更是我所高兴的。主考官：你是否打算将来继续深造？小李：我想先工作几年，积累一些经验，发现自身的一些不足，然后再进一步“充电”。主考官：你有什么问题要问吗？小李：不知贵公司什么时候能给我一个明确的结果？主考官：一个星期内我们将公布此次招聘的毕业生名单。小李：谢谢你们，我可以走了吗？主考官：再见。

对这次面试过程的评价是（）。

A.缺点太多

B.效果很差

C.非常成功

D.基本正常

在一片农田中，长有很多杂草，还有粘虫、青蛙、蛇等动物活动，某中学生物兴趣小组对这一农田进行研究，根据所学知识回答问题。

该农田中，所有生物的种群的集合称为（），其物种数目的多少叫（）。

DDC控制器的模块地址常用硬件和软件两种设定的方法，如果控制器使用了专用的通信芯片，它的地址获得的方法是（）。

A、拨码开关实现

B、跳线端子实现

C、不需要设定

D、由通信芯片提供