用蒸馏水洗涤玻璃仪器的原则是少量多次,即用少量的水洗涤多次,至少洗涤()以上。A、两

题型:单项选择题

问题:

用蒸馏水洗涤玻璃仪器的原则是少量多次,即用少量的水洗涤多次,至少洗涤()以上。

A、两次

B、三次

C、四次

D、五次

考点:证券从业资格考试煤质化验高级工煤质化验高级工题库
题型:单项选择题

静电喷漆技术具有效率高,浪费少,质量好,有利于工人健康等优点,其装置如图所示.A、B为两块平行金属板,间距d=0.50m,两板间有方向由B指向A,大小为E=l.0×l03N/C的匀强电场.在A板的中央放置一个安全接地的静电油漆喷枪P.油漆喷枪的半圆形喷嘴可向各个方向均匀地喷出带电油漆微粒,油漆微粒的初速度大小均为vo=2.0m/s,质量m=5.0×l0-16kg、带电量为q=-2.0×10-16C.微粒的重力和所受空气阻力均不计,油漆微粒最后都落在金属板B上.试求:

(1)电场力对每个微粒所做的功;

(2)微粒到达B极所需的最长时间:

(3)微粒最后落在B板上所形成图形的面积大小.

题型:单项选择题

阅读理解。

     根据短文内容,从短文后的选项cfl选出能填入空白处的最佳选项。选项中有两项为多

选项。

      1  

    With Father's Day 20 lI here,find out how the holiday started,why Dad doesn't mind being

shortchanged on gifts,and more.

    Father's Day traditionally takes a backseat to Mother's Day,and,for the most part,dads are

cool with that,experts say.Nevertheless,as traditional roles around the house gradually change.

fathers are gaining more attention on their special day,at least as measured in the monetary value

of gifts estimated to be given on June l 9,20 11,when the holiday will be celebrated in dozens of

countries.    

       2   

    Where did Valentine's Day come from?What does it cost?And why do we fall for it.year

after year?

    Where did this most popular day for couples come from?And how does it come into beings,

year after year?Noel Lenski,professor of the University of Colorado,said the lovers'holiday traces

its roots to raucous annual Roman festivals held every year on February l 5 and remained wildly

popular well into the fifth century A.D.

      3   

    After 40 years,outsourced activism is replacing traditional Earth Day activities,and green's gone

mainstream,experts say.So what's the point?

    The first Earth Day in l970 was a raucous, radical teach--in that helped spur clean-air, clean-water,

and endangered species legislation in the United States.Now,40 years later,Earth Day is every day,

as the saying goes. The thing is, it's also everyday-- environmentalism has become a routine with

greenness as much a marketing tactic as a moral pursuit.

      4   

    How did Founding Fathers Celebrate 4th of July?How many 4th of July fireworks explode each

year?Answers and more.

    Cookouts,fireworks,and,of course,a chance to wish Uncle Sam a big "happy birthday"-the day

means summer in full swing across the United States and beyond.Besides the founders of the US,

Fireworks,first authorized by Congress in l777,are another legacy.More than l 4,000 fireworks

displays light up U.S.skies each year.    '

      5   

    Before the big dinner,debunk the myths-for starters,the first"real" Thanksgiving wasn't until the

l800s-and get to the roots of Thanksgiving 2010.

    Some 242 million turkeys were raised in the U.S.in 2010 for slaughter,according to the U.S.

Depmment of Agriculture's National Agricultural Statistics Service.Last year'S birds were worth

about U.S.$3.6 billion. Before the big dinner, debunk the myths,we need to know that the first

"real"U.S.Thanksgiving wasn't until the l800s and get to the roots of Thanksgiving 2010.

A. 4th of July Facts:1 st Fests,Number of Fireworks.More

B. Father's Day Shortchanged? Humble History,Fewer Gifts

C. Is the Spring Festival changing little by little?

D. Thanksgiving 2010 Myths and Facts

E. Valentine's Day Facts: Gifts,History,and Love Science

F. The fact of the Intrnational Labour Day

G. Earth Day at 40: What Good Is It Now?

题型:单项选择题

单频GPS卫星导航仪定位精度为()。

A.15~30m

B.0.05~0.1nmile

C.1m

D.100m

题型:单项选择题

男性,76岁。排尿困难3年,多次尿潴留,每次导尿后拔除尿管仍不能排尿,现留置导尿管。查体示肛门指诊前列腺Ⅱ。增生,弹性差。B超示双肾无积水。前列腺Ⅱ。增大,患者不能平卧,心功不全,有慢性气管炎病史。该患者最佳治疗方法是()

A.经膀胱前列腺切除术

B.耻骨后膀胱前列腺切除术

C.经 * * 前列腺电切除

D.局麻下膀胱造瘘双睾丸切除术

E.继续留置导尿

题型:单项选择题

一个数据库有多个外模式,有______内模式。

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