通常选定精度要求较高的面或主要加工面作为第一划线位置,其目的是为了()A、工件校正时

题型:单项选择题

问题:

通常选定精度要求较高的面或主要加工面作为第一划线位置,其目的是为了()

A、工件校正时,比较准确

B、保证它们有足够的加工余量,加工后便于达到设计要求

C、便于全面了解和校正,并能够划出大部分的加工线

考点:模具制造工中级模具制造工中级模具制造工题库
题型:单项选择题

Father of TV

Invention of television began in 1922 in Rigby, Idaho, the hometown of Philo Farnsworth. At the age of 16, Philo was a very shy boy. Only his science teacher, Justin Tolman, realized that Philo was a special person.

One day after school Mr. Tolman found Philo in the classroom. The boy was making drawings on the chalkboard.

“What are you doing?” Mr. Tolman asked with interest, “What are these drawings?”

“I want to invent things,” Philo answered, “and these are the drawings of one of my first inventions. I have an idea for a way of sending pictures through the air. Please, just let me tell you about it. You are the only person who can understand what I have done.” In the school library Philo had read about a man who had worked on an idea for television, but had failed. Philo was sure that his own idea was better and that he could succeed.

Mr. Tolman was not sure and asked Philo many questions about the drawings. Giving facts and figures, Philo answered every question.

In 1926, Philo sent his drawings to Washington, along with a letter asking for the patent rights on television. Since then, television has become an important business all over the world.

小题1:When he lived in his hometown, Philo was _______.

A.quite different from others

B.an active boy

C.an inventor

D.a hard-working boy小题2:When Philo said “You are the only person who can understand what I have done.” In Paragraph 4, his mood was ________.

A.discouraged

B.trusting

C.guilty

D.hopeless小题3:It took Philo ____ to invent the television.

A.2 years

B.6 years

C.4 years

D.8 years小题4:When Mr. Tolman saw Philo’s drawing, he _______.

A.did not believe it was Philo’s invention

B.believed Philo could succeed

C.believed Philo was a special person

D.did not believe Philo could succeed

题型:单项选择题

以高聚物为基础,加入某些助剂和填料混炼而成的可塑性材料,主要用作结构材料,该材料称为()。

A、塑料

B、橡胶

C、纤维

D、合成树脂

题型:单项选择题

该婴儿的月龄为

A.4~5个月
B.5~6个月
C.6~7个月
D.8~10个月
E.10~12个月

题型:单项选择题

患者,男,18岁。因高热,胸痛,咳铁锈色痰入院,检查:急性热病病容,体温40℃,脉搏102次/分,X线胸片示左上肺大片片状阴影,白细胞19×109/L。治疗应首选()

A.青霉素加麻杏石甘汤

B.输液加给氧

C.糖皮质激素

D.红霉素加庆大霉素

E.病毒唑加退热药

题型:单项选择题

患者男性,25岁。平静状态下,没有任何先兆,心跳突然加速,脉搏多在200次/分,伴有心慌、头晕、乏力,偶尔出现胸痛、呼吸困难。心电图检查后诊断为阵发性室上性心动过速,可用于治疗的药物是()

A.阿托品

B.哌唑嗪

C.新斯的明

D.异丙肾上腺素

E.肾上腺素

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