使用特细砂配制混凝土时,应选用()。 A.较低砂率 B.较高砂率 C.高流动性拌合物

题型:单项选择题

问题:

使用特细砂配制混凝土时,应选用()。

A.较低砂率

B.较高砂率

C.高流动性拌合物

D.低水灰比

考点:混凝土试验员考试混凝土基础知识及配合比设计混凝土基础知识及配合比设计题库
题型:单项选择题

23岁男性农民,11月份因发热、头痛、呕吐3天入院。体检:面颈部潮红,双腋下少许出血点,化验:尿常规蛋白(+),红细胞3~10个/HP,末梢血象:WBC 23.0×109/L,异型淋巴细胞10%;PLT 48× 109/L。

住院2天后,热退但症状加重,出血点增加,四肢厥冷,脉搏细弱,BP: 80/60mmHg,此时对该患者的治疗原则是

A.以扩容为主

B.以应用血管活性药物为主

C.以应用激素为主

D.以纠正酸中毒为主

E.以输入胶体液为主

题型:单项选择题

方程x3-6x2+9x-10=0与y=-8的交点个数是(  )

A.3

B.2

C.1

D.0

题型:单项选择题

如右图甲所示,间距为d的平行金属板MN与一对光滑的平行导轨相连,平行导轨间距L=d/2,一根导体棒ab以一定的初速度向右匀速运动,棒的右侧存在一个垂直纸面向里,大小为B的匀强磁场。棒进入磁场的同时,粒子源P释放一个初速度为0的带电粒子,已知带电粒子质量为m,电量为q.粒子能从N板加速到M板,并从M板上的一个小孔穿出。在板的上方,有一个环形区域内存在大小也为B,垂直纸面向外的匀强磁场。已知外圆半径为2d, 里圆半径为d.两圆的圆心与小孔重合(粒子重力不计)

(1)判断带电粒子的正负,并求当ab棒的速度为v0时,粒子到达M板的速度v;

(2)若要求粒子不能从外圆边界飞出,则v0的取值范围是多少?

(3)若棒ab的速度v0只能是,则为使粒子不从外圆飞出,则可以控制导轨区域磁场的宽度S(如图乙所示),那该磁场宽度S应控制在多少范围内

题型:单项选择题

简述输液的常见并发症和注意事项。

题型:单项选择题

During the early years of American settlement, a new form of English was beginning to develop in the islands of the West Indies and the southern part of the mainland, spoken by the black population. The beginning of the seventeenth century saw the happening of the slave trade. Ships from Europe travelled to the West African coast, where they exchanged cheap goods for black slaves. The slaves were shipped in terrible conditions to the Caribbean islands and the American coast, where they were in turn exchanged for such products as sugar and molasses(糖蜜). The ships then returned to England, completing an “Atlantic triangle”of journeys, and the process began again. Britain and the United States had outlawed the slave trade by 1865, but by that time, nearly 200 years of trading had taken place. By the middle of the nineteenth century, there were over four million black slaves in America.

The policy of the slave-traders was to bring people of different language backgrounds together in the ships, to make it difficult for groups to plan rebellion. The result was the growth of several pidgin (混杂语言) forms of communication, and in particular a pidgin between the slaves and the sailors many of whom spoken English. Once arriving in the Caribbean, this pidgin English continued to act as a major means of communication between teh black population and the new landowners, and among the blacks themselves. Then, when children came to be born, the pidgin became their mother tongue, thus producing the first black Creole(克里奥尔语) speech in the region. This Creole English rapidly came to be used throughout the cotton plantations (种植园), and in the coastal towns and islands.

小题1:Which of the following shows the route of slave trade correctly?

A.EuropeWest African coastthe Caribbean islands and the American coastEurope

B.EuropeWest African coastEuropethe Caribbean islands and the American coast

C.West African coastEuropethe Caribbean islands and the American coastEurope

D.West African coastEuropethe Caribbean islands and the American coastWest African coast小题2:It can be inferred that the slaves in the same ship ____.

A.didn’t communicate with each other

B.could understand several languages

C.spoke different languages

D.came from the same place小题3:Creole speech comes from _____.

A.Spanish and English

B.English and an African language

C.a European language and an American language

D.an African language and an American language小题4:What is the text mainly about?

A.The history of slave trade.

B.“Atlantic triangle” of journeys.

C.Languages spoken in America

D.The birth of black English

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