第一部分选择题(共30分) 一、单项选择题(本大题共10小题,每小题3分,共30分) 在每小题列出的四个选项中只有一个是符合题目要求的.请将其代码填在题后的括号内。错选或未选均无分。 串联谐振电路,固有谐振频率取决于 A电源电压幅值 B电源电压的初始相位 C.电源电压频率

Atomic Structure All natural and most synthetic substances on earth are made from the ninety naturally occurring chemical elements. An atom is the smallest particle into which an element can be divided while still retaining the chemical characteristics of that element (fig 3. 1). The nucleus, at the center of the atom contains one or more particles with a positive electrical charge(protons fif and usually some particles of similar mass that have no charge(neutrons

Language Definition of human language ----A system of vocal symbols used human communication

一、判断下列说法是否正确,用“√”或“”表示判断结果。 (1)在图T8.1所示方框图中,若中F180°,则只有当中A=±180°时,电路才能产生正弦波振荡。()

3.1 X(eo)=2xnJe-jon where x[n] is a real sequence. Therefore X(e)=Rl∑xnlo/。 ∑xR(-mu)=∑ x[n]cos(on),and xmm)=m∑刈nm∑刈mc-m)=-2 xn] sin(oon) Since cos(on)and sin(on)are, respectively, even and odd functions of o, Xre(eJo) is an even function of o

Through the study of these two periods of class, the students should understand the text correctly. The new words should be read fluently. The new words and the expressions in the text should be learnt by heart

l. Pre-reading Task ll. Related Information llI. Detailed Study lV. Outline& Summary V Home Assignment

I Pre-Reading Task How much do you know about the Internet? 2. What do people usually do on the Internet 3. What has made the Internet possible?

Unit One Text A l. Pre-reading Task ll. Related\\ Information lll. Outline& Summary IV. Detailed Study V. Home Assignment By Dai Mingyuan

People from different cultures have d ifferent ideas about the food. We may have our food likes and dislikes because of nutritious and religious reasons. However, far beyond these; they are also a result of the ways of life of d ifferent people. For example