在纯电容电路中,电压与电流的关系是:()A、纯电容电路的电压与电流频率相同; B、电

题型:多项选择题

问题:

在纯电容电路中,电压与电流的关系是:()

A、纯电容电路的电压与电流频率相同;

B、电流的相位滞后于外加电压u为π/2(即90°);

C、电流的相位超前于外加电压u为π/2(即90°);

D、电压与电流有效值的关系也具有欧姆定律的形式。

考点:农网配电营业工考试农网配电营业工高级工农网配电营业工高级工题库
题型:多项选择题

已知等比数列{xn}的各项为不等于1的正数,数列{yn}满足ynlogxna=2(a>0,a≠1),设y3=18,y6=12.

(1)求数列{yn}的前多少项和最大,最大值为多少?

(2)试判断是否存在自然数M,使当n>M时,xn>1恒成立?若存在,求出相应的M,若不存在,请说明理由;

(3)令an=logxnxn+1(n>13,n∈N),试判断数列{an}的增减性?

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课文背诵

People have been  1 cycling in Amsterdam for years. It is a good city for cycling because it is flat and therefore is convenient for bikes. There are also plenty of places for bicycle parking and most streets in the city centre have a bicycle path. Today some people cal the “City of Bicycles” because of   2  there.

In the 1960s, a group of cycling fans had an idea. They believed that it would be better for everybody if cars weren’t allowed in the city centre and only bicycles were.

They were hopeful that this would help to save energy,   3  and  4 . The group  5 and placed them in lots of neighborhoods around Amsterdam for people to use. Anyone was allowed to take them and use them for short journeys. Wherever someone finished a journey they would leave the bike there for someone else to use. The problem was that it didn’t work-thieves took all the bicycles within weeks!

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人们对医疗行为进行道德价值判断是通过

A.医德活动

B.医德教育

C.医德修养

D.医德评价

E.医德境界

题型:多项选择题

— What _______ do you have for Daniel?

— I think he should study harder than before.

A.news

B.advice

C.help

D.idea

题型:多项选择题

中国第一个黄金时代是()。

A.唐朝时期

B.三国时期

C.战国时期

D.宋朝时期

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