问题的提出 1、计量经济学模型,需要经常考虑属性因素的影响。例如,职业、战争与和平、繁荣与萧条、文化程度、灾害、季节 2、属性因素往往很难直接度量它们的大小。只能给出它们的“Yes—D=1”或”No一D=0”、或者它们的程度或等级

一、单项选择题 1、操作系统是一种(B)。 A.应用软件B.系统软件C.通用软件D.工具软件 2、操作系统是一组(C)。 A.文件管理程序B.中断处理程序 C.资源管理程序D.设备管理程序

9.1A/D转换器接口 9.2D/A转换器接口

I. Vocabulary and structure 1. On my way to school, I saw people _advertisements and sample products. A. conveying B.creating C. discarding D. distributing 2. The professor thought that I was making good progress in my studies and told me to my good work A. keep up B. go ahead with C. hold back D. come up with

DATA1 园D+ GN国S DATA XTAL2 TAL1 四GL DATA ALE 10 19 EOT_N csN回

Lecture D34 Coupled Oscillators Spring-Mass System(Undamped/Unforced)

Lecture D32: Damped Free Vibration Spring-Dashpot-Mass System k Spring Force Fs =-kx, k>0 Dashpot Fd =-cx, c>0 Newton's Second Law (mx =EF) mx +cx+kx (Define)Natural Frequency wn=k/m,and

Lecture D33: Forced Vibration Fosinwt m Spring Force Fs =-kx, k>0 Dashpot Fd =-ci, c>0 Forcing Fext Fo sin wt Newton's Second Law (mix =CF) mx+cx+kx= Fo sin wt =k/m,=c/(2mwn)

In lecture D28, we derived three basic relationships embodying Kepler's laws: Equation for the orbit trajectory

一、选择题:1~8小题,每小题4分,共32分,下列每小题给出的四个选项中,只有一项 符合题目要求,把所选项前的字母填在题后的括号内 (1)设f(x)=x2(x-1)(x-2),求f(x)的零点个数() (A)0 (B)1 (C)2 (D)3 解:(D)