1 Graphs and Trees The following two definitions of a tree are equivalent Definition 1: A tree is an acyclic graph of n vertices that has n-1 edges Definition 2: A tree is a connected graph such that Vu, v E V, there is a unique path connecting u to u. In general, when we want to show the equivalence of two definitions, we must show

1 Unstacking Here is another wildly fun 6.042 game that's surely about to sweep the nation! You begin with a stack of n boxes. Then you make a sequence of moves. In each move, you divide one stack of boxes into two nonempty stacks. The game ends when you have n stacks, each containing a single box You earn points for each move; in particular, if you divide one stack of height a b into two stacks with heights a and b, then you score

7.1 I/O接口扩展概述 7.2 MCS-51与可编程并行I/O芯片8255A的接口 7.3 显示器键盘接口 7.2.2 工作方式选择控制字及C口置位/复位控制字 7.2.3 8255A的三种工作方式 7.2.4 MCS-51单片机和8255A的接口 7.3 用74LSTTL电路扩展并行I/O口 11.1 MCS-51与DAC的接口 11.2 MCS-51与ADC的接口 11.3.MCS-51与ADC0809的接口

第一节 崩塌 6.1 Collapse 6.1.1 Types of collapse 6.1.2 Forming conditions of collapse 6.1.3 Accumulation and landforms of collapse 第二节 滑坡 6.2 Landslide 6.2.1 The shape of a landslide 6.2.2 Influence factors to a landslide 6.2.3 Types of a landslide 6.2.4 The development of a landslide 6.2.5 Prevention of a landslide

1、解： (1) P｛只订购 A 的｝=P{A(B∪C)}＝P(A)-{P(AB)+P(AC)-P(ABC)}=0.45-0.1.-0.08+0.03=0.30. (2) P｛只订购 A 及 B 的｝=P{AB}-C｝=P(AB)-P(ABC)=0.10-0.03=0.07 (3) P｛只订购 A 的｝=0.30

材料工程基础试卷B答案 一、选择题(共15题,每题2分,共30分) .A 2. 3.A 4.C 5.B 6B7B8C9.A10.C 11C12.A13.B14.A15.B

Text A: fantasy, suspicion, injection, deputy, considerate, restore, estate, fantastic, multiple, furnish, deceive, commission, substantial, arrest, motive, justify exceeding, swear, disguise, switch e Text B: romantics, mysterious, e it, sigh, simplify, standpoint, heave, shiver, 2. Key phrases and expressions Text A: raise a glass to, turn out, buy up, live out, add on, fix up, sell sth at a loss Text B: read about, for one thing, in the night, make an appointment, switch on, raise the devil answer the door. stare after 3. Key structures

Introduction 1-2 Definition of a Fluid Fluid mechanics: the behavior of The solid object will no change fluids at rest and in motion inside the a closed container A fluid is a substance that deforms continuously under the application The liquid will change its shape of a shear(tangential) stress no to conform to that of the matter how small the shear stress container and will take on the may be

Functional groups The structural features that make it possible to classify compounds by reactivity are called functional groups. A functional group is a part of a larger molecule and is composed of an atom or a group of atoms that have a characteristic chemical behavior. The Chemistry of every organic molecules

设矩阵A∈Rn,如果存在数入∈C及非零向量x∈C满足方程 Ax∈x,则称λ为矩阵A的一个特征值,称为矩阵A的相应于特 征值λ的特征向量。为简单起见,下称,x为矩阵A的一特征对。 特征值的计算,直接从特征方程()=det-A)=0出发会遇到很 大困难,当n稍大一些,行列式展开本身就很不容易,随后是高次代数 方程求解。因此,矩阵特征值的求解,主要是数值解法