科技英语入门课后答案.doc

Unit One Mathematics and Physics 2. Fill in the blanks according to the above passages. (1) agricultural; technological (2) matter; energy (3) Notations; propositions (4) deductions; computation (5) forces (6) economics; quantities (7) electromagnetism (8) sound; transmitted; produced (9) optics (10) atom; nucleus; particles 3. Judge whether the following statements are true or false, and correct the mistakes in the false statements. (1) false; all (2) false; three two, and electricity magnetism mechanics (3) true (4) false; sound light (5) true (6) false; known unknown 4. Translate the following technological phrases into English or Chinese. (1) 数学 mathematics (2) 高等代数 higher algebra (3) 微分方程 differential equation (4) 解析几何 analytical geometry (5) 逻辑推理 logical deduction (6) 几何定理 geometrical theorem (7) physical laws 物理定律 (8) the established law 既成定律 (9) the law of conservation of energy 能量守恒定律 (10) Newtons theory of mechanics 牛顿力学定律 5. Make sentences using the following phrases. (1) play a role in Electricity plays a great role in our daily life. (2) belong to These books belong to the library. (3) deal with I think we should work out a strategy to deal with this situation. (4) carry out It takes much time to carry out a test.Unit Two Computer Software 2. Fill in the blanks with the words or phrases given in the list below. Change the word form where necessary. (1) Algorithms (2) whichever (3) starts by; subproblems (4) so that (5) known as (6) so far (7) Note that (8) focuses on 3. Introduction and translation of specific expressions. (1) The security of users in the local network of an enterprise is no longer limited to inside firewall, as shown in Fig. 2-1. (2) As Fig. 2-1 shows, the OSI model is a reference network model provided by the International Standard Organization.Unit Three Computer Networks 2. Fill in the blanks with the words or phrases given in the list below. Change the word form where necessary. (1) transfer (2) interact (3) compatibility (4) configuration (5) facilitate (6) In one sense (7) productive (8) refers to; protocols (9) stands for 3. Match the word or acronym with the definition or in the appropriate blank. (1) WAN (2) Gateway (3) bus topology (4) Telnet (5) broadband (6) HTTP (7) LAN (8) UDP (9) TCP (10) IP 4. Introduction and translation of specific expressions. (1) 物体受热时，分子的平均速度提高。 It is heating which increases the average velocity of molecules in a body. (2) 月球的确具有引力。 The moon does have gravity. (3) 就在我们闭合电路的那一瞬间，电流开始流动。 The very moment when the circuit is closed makes electricity flow. (4) 电使得许许多多的东西成为可能。 The one makes various things possible is electricity.Unit Four Analog Electronics 2. Put the following phrases into English. (1) 模拟电子技术 analog electronics technology (2) 双极型晶体管 bipolar transistor (3) 晶体管效应 transistor effect (4) 基极电流 base current (5) 增强型金属氧化物半导体 enhancement metal-oxide-semiconductor (6) 耗尽型金属氧化物半导体 exhausted metal-oxide-semiconductor (7) P沟道 P slot (8) 数字集成电路 digital integrated circuit (9) 放大器 amplifier (10) 直流电路 DC circuit (11) 集成电路 integrated circuit (12) 逆时针方向 anti-clockwise (13) 散热片 heat sink (14) 插座 holder (15) 焊接 solder (16) 引脚 pin 3. Translate the following sentences into Chinese or English. (1) According to the voltage condition, there are two kinds of MOS transistors: enhancement and exhausted. 根据电压的状况，金属氧化物半导体晶体管可以分为两种：增强型和耗尽型。 (2) Based on transistors, various circuits are manufactured which involve practical amplifiers, biasing circuits, operational amplifiers circuit, and other circuits: rectification, regulation and DC power supplies. 基于晶体管，（人们）制成了各种各样的电路，包括实用放大器、偏置电路、运算放大电路和其他的电路：整流电路、稳压电路和直流电源。 (3) 今天我们更多地用金属氧化物半导体（MOS）晶体管来做集成电路。 Nowadays, more and more metal-oxide-semiconductor transistors are used to make integrated circuits. (4) 一般的集成电路芯片的引脚个数有14脚、20脚、28脚、甚至更多。他们大多以逆时针方向排列。 General integrated circuit chips have 14 pins, 20 pins, 28 pins, or even more. Most of the pins are arranged anti-clockwise.Unit Seven Communication Modulation 2. We can write wireless electromagnetic wave as the following math expression. Can you point out which is amplitude, frequency and phase? (1) V=coswt Amplitude: 1 Frequency: w/2pi Phase: 0 (2) V=Acoswt Amplitude: A Frequency: w/2pi Phase: 0 (3) V=Acos(wt+phi) Amplitude: A Frequency: w/2pi Phase: phi (4) V=Asin(wt+phi) Amplitude: A Frequency: w/2pi Phase: phi-2pi 3. Judge the following modulation index whether bigger or less than 1. (1) m1 (3) m=1 4. Translate the following sentences or phrases into Chinese. (1) We will consider three cases: amplitude modulation (AM), in which the amplitude A varies with time; frequency modulation (FM), in which the frequency w varies with time; or phase modulation (PM), in which the phase phi varies with time. 我们考虑三种情况：调幅，其中幅度A随时间变化；调频，其中频率w随时间变化；调相，其中相位phi随时间变化。 (2) The constant m is called the modulation index. It specifies the fractional variation of the modulation function about its mean value. 常数m叫做调制指数。它记录调制函数平均值的百分比变化。 (3) speech waveform 语音波形 (4) data telephone line 电话线 (5) information-carrying waveform 承载信息的波形 (6) trapezoidal wave 梯形波 (7) percent modulation 调制百分比 (8) peak-to-peak 峰到峰 (9) over modulated 过调制 (10) frequency spectrum 频谱 5. Translate the following phrases or sentences into English. (1) 振幅调制 amplitude modulation (2) 脉冲调制 pulse modulation (3) 平均功率 average power (4) 周期信号 periodic signal (5) 光波长 wavelength of light (6) 一个完善的周期波，例如正弦波不能携带任何信息。 A perfectly periodic waveform, such as a sine wave cannot carry any information. (7) 每当波形可表示为一系列正弦波的叠加时，各正弦波的振幅可以用所谓频谱形象地