问题 选择题
如图所示,理想变压器原、副线圈的匝数比为10:1,b是原线圈的中心接头,电压表V和电流表A均为理想电表.从某时刻开始在原线圈c、d两端加上交变电压,其瞬时值表达式为u=220sin100πt(V).下列说法正确的是(  )

A.当单刀双掷开关与a连接时,电压表的示数为22V

B.当单刀双掷开关与b连接时,电压表的示数为11V

C.当单刀双掷开关与a连接,滑动变阻器触头P向上移动的过程中,电压表的示数不变,电流表的示数变大

D.单刀掷开关由a扳向b时(滑动变阻器触头P不动),电压表和电流表的示数均变大

答案

答案:D

单项选择题 A1/A2型题
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Microsoft founder Bill Gates has opened up about being a parent,stating that 13 is an appropriate age for a child’s first cell phone.

The 57­year­old,father­of­three,revealed on The Today Show that his children Jennifer and Rory were not allowed phones until their 13th birthday and his youngest daughter Phoebe is still waiting for one.

“We’ve chosen in our family that it’s 13 where you get a phone,” the self­made billionaire explained.

He said as a result his children often return home from school complaining,“All the other kids have one.I’m the only one without one.It’s so embarrassing.”

Asked if he keeps passwords to his son and daughters’ email and Facebook accounts,Mr Gates said that he doesn’t for Jennifer,16,who he describes as “independent”.He admitted that monitoring online activity is “a very tricky issue for parents now”.

Despite their vast wealth Mr and Mrs Gates,who live in Lake Medina,have  said  they  want  to give  their children  as  normal an upbringing as possible.

It was previously reported that their youngsters have to complete household chores and are given a modest amount of pocket money.

And in 2010 Mr Gates said that he intends to give most of his $61 billion fortune away rather than hand it down.“That wouldn’t be good either for my kids or society,” he said.

Also during the Today interview with host Matt Lauer,Mr Gates,who stepped down from Microsoft in 2008 to concentrate on philanthropy,said that helping others gives him the same excitement as creating software.

“What you really feel is what you’ve achieved.If a piece of software gets out there and lots of people love it—it lets them get their work done in better ways—that’s exciting,” he explained.

小题1:Bill Gates will not let his children own a cell phone________.

A.until they reach the age of 13

B.if they don’t really need one

C.unless they do some housework

D.before they become independent小题2:Which of the following is true about Bill Gates’ children?

A.All his children now have cell phones.

B.Phoebe has her own cell phone.

C.They are not given any pocket money.

D.Jennifer can use the Internet freely.小题3:What does the underlined word “That” refer to in the text?

A.Being a parent as a billionaire.

B.Handing all his money down to his children.

C.Allowing his children to have their phones.

D.Giving away all his money to good causes.小题4:What can we learn about Bill Gates from the text?

A.He is a warm­hearted father to his children.

B.He has created a lot of software since 2008.

C.He now devotes himself to helping others

D.He cares more about money than anything else.小题5:What is the text mainly about?

A.How Bill Gates made himself a billionaire.

B.How Bill Gates deals with his money.

C.How Bill Gates managed his business.

D.How Bill Gates brings up his children.