更多"验证在整个axy平面内（2xy+3x²+1）dx+（x&su"的相关试题:
[简答题]验证在整个oxy平面内
(4x3y3-3y2+5)dx+(3x4y2-6xy-)dy
是某个二元函数u(x，y)的全微分，并求这样的一个u(x，y)．
[单项选择]系统测试是针对整个产品系统进行的测试，目的是验证系统是否满足______的定义。
A. 详细设计
B. 概要设计
C. 需求规格
D. 数据库设计
[单项选择]______把整个软件开发流程分成多个阶段，每一个阶段都由目标设定、风险分析、开发和有效性验证及评审构成。
A. 原型模型
B. 瀑布模型
C. 螺旋模型
D. V模型
[单项选择]Wolfe分型中DY型的主要表现为
A. 几乎完全由脂肪构成
B. 自乳头伸向后方较明显的多数条索状影，余为脂肪，前者范围小于乳腺体积1/4
C. 条索影范围超过乳腺体积1/4
D. 条索影范围超过乳腺体积1/4，但小于1/2
E. 乳内主要为不规则性的片状密度增高影占据
[多项选择]设计验证的目的是验证设计输出是否满足设计输入的要求，验证活动包括( )。
A. 变换计算方法进行设计计算
B. 将新设计与已证实的类似设计进行比较
C. 对不同设计过程的设计成果进行评审
D. 对不符合验证要求的设计进行改进
E. 对性能和强度进行试验和证实
[填空题]目前已有产品的个人特征验证技术有手书签字验证、______、语音验证、______、虹膜图样验证、脸型验证等。
[多项选择]在逻辑框架水平逻辑层次上，对应验证指标的是验证手段，验证方法可按( )划分。
A. 数据收集类型
B. 咨询信息来源
C. 数据收集技巧
D. 咨询信息控制
E. 数据源控制
[简答题]Questions 1-9
Color in textiles is produced by dyeing, by printing, or by painting. Until thenineteenth century, all dyes were derived from vegetable or, more rarely, animalor mineral sources,
Since madder plants could be grown practically everywhere, the roots of some
species of the madder plant family were used from the earliest period to produce a wholerange of reds. Red animal dyes, derived! from certain species of scale insects, were alsohighly valued from ancient times through the Middle Ages. Blues were obtained fromindigo, which was widely .cultivated in India and exported from there, and from woad,a plant common in Europe and also used in the Near East from the beginning of the Christian era. Before the first, nonfading "solid" green was invented in the earlynineteenth century, greens were achieved by the overdyeing or overprinting of yellowand blue. However, yellow dyes± whether from weld or some other plant source suchas saffron or turmeric, invariably fade or disappear.
A. A．Animals
B． Minerals
C．Plants
D．Chemicals
