写作答案-科英.doc

写作练习参考答案 练习 1 (on page 8) II. 1. Nonlinear distortion can be caused by too large an input signal. 2. Using the definition of slope, we can derive the equation which represents a straight line. 3. The expression f(x + h) – f(x) is frequently used in the study of calculus. 4. An equation which can be written in the following form is known as a linear equation in one unknown. 5. In a computer, the tendency is to operate at as high a clock rate as possible. 6. The voltage across this capacitor is a few hundredths of a volt. 7. The output of the factory ten years ago was only one fifth what it is now [或：… only one fifth its present output]. 8. The difference between these two values is 13 parts in 104. 9. Tin does not have as high a melting point as lead (does). 10. This average velocity is half the final velocity. 11. It is necessary to find how long a time it takes [或：is required; is needed; is necessary] to solve this equation. 12. This wire is four times thicker than that one. 13. Electricity can be easily changed into other forms of energy. 14. In 1831, Joseph Henry in the United States discovered the phenomenon of electromagnetic induction. 15. A receiver consists of several units [或：parts]. III. The newly designed instrument is good in quality [或：… is of good quality]. This engine needs to be cleaned [或：cleaning]. This running machine will stop of itself in a minute or two [或：… in one or two minutes]. In this case, the input does not fall; the output does not fall, either. [或：…; neither [nor] does the output.] The resistance of a conductor depends not only on the material of which the conductor is made, but also on the size and temperature of the conductor. Another comsat was launched on the morning of the 8th of October. IV. The period with which a body undergoes simple harmonic motion is the time required for it to make one complete oscillation. In the case of a spring, the period is the time the spring spends in going from its maximum ex