When we talk, we don't talk in single words but in groups of words spoken continuously. These groups of words which are closely connected in meaning and in grammar are called sense groups. sense group is tone-group-(语调群) in intonation. long sentence can be cut up into two or more tone-groups We may make a short pause after each group, but not during the group

1.简述图1所示的降压斩波电路的工作原理。 2.在图1所示的降压斩波电路中,已知E=200V,R=10,L值极大,E=30V。采用脉宽调制控制方式,当T=50us,ton=20us时,计算输出电压平均值U、输出电流平均值I

一、基本概念 1.对于曲线C的无论怎样的分割T,如果存在有限极限limS=s,则称曲线C是可求长的,并把s定义为曲线C的长度

常见的小儿内分泌疾病,以往称为呆 小病或克汀病。我国发病率1/4000 T4,sH 生长落后,智能障碍

一、(10分)已知系统的传递函数=2且初始条件为c()=1,()=0R(s)s2+3s+2试求阶跃输入r(t)=1(1)作用时,系统的输出响应()

Unit 6 Day-to-day work 6.1 Talking about your work (1)Listening Listen to Ana Campos talking about her working hours. Are these statements true (T)or false(F)? 1 She starts works at 7.30. 2 She finishes work at 4.00 3 She has lunch at 12.00. 4 She has one hour for lunch. 5 She works a 40-hour week

How do you start? Assume the audience is technically competent, but isn't familiar with your project? What do they need to know first?

第一节施工准备工作和施工放样 第二t节各种类型涵洞施工技术 第三节涵洞附属工程的施工

一、概念的引入 例:设有一弹簧下挂一重物,如果使物体具有一个初 始速度v≠0,物体便离开平衡位置,并在平衡位置 附近作上下振动.试确定物体的振动规律x=x(t) 解受力分析

一、问题的提出 1,当-π≤t<0