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

多项选择题
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Home to me means a sense of familiarity and nostalgia(怀旧). It's fun to come home. It looks the same. It smells the same. You'll realize what's changed is you. Home is where we can remember pain, live, and some other experiences; We parted here; My parents met here; I won three championships here.

If I close my eyes, I can still have a clear picture in mind of my first home. I walk in the door and see a brown sofa surrounding a low glass-top wooden table. To the right of the living room is my first bedroom. It's empty, but it's where my earliest memories are.

There is the dining room table where I celebrated birthdays, and where I cried on Halloween-when I didn't want to wear the skirt my mother made for me. I always liked standing on that table because it made me feel tall and strong. If I sit at this table, I can see my favorite room in the house, my parents' room. It is simple: a brown wooden dresser lines the right side of the wall next to a television and a couple of photos of my grandparents on each side. Their bed is my safe zone. I can jump on it anytime - waking up my parents if I am scared or if I have an important announcement that cannot wait until the morning.

I'm lucky because I know my first home still exists. It exists in my mind and heart, on a physical property (住宅) on West 64th street on the western edge of Los Angeles. It is proof I lived, I grew and I learned.

Sometimes when I feel lost, I lie down and shut my eyes, and I go home. I know it's where I'll find my family, my dogs, and my belongings. I purposely leave the window open at night because I know I'll be blamed by Mom. But I don't mind, because I want to hear her say my name, which reminds me I'm home.

小题1:Why does the author call her parents' bed her "safe zone"(Paragraph 3)?

A.It is her favorite place to play.

B.Her needs can be satisfied there.

C.Her grandparents' photos are lined on each side.

D.Her parents always play together with her there.小题2:What can be learned from the passage?

A.The old furniture is still in the author's fist bedroom.

B.The author can still visit her first physical home in Los Angeles.

C.The author's favorite room in her first home is the dining room.

D.Many people of the author's age can still find their first physical homes.小题3:Sometimes when she feels lost, the author will _______.

A.Open the window at night

B.lie down in bed to have a dream

C.try to bring back a sense of home

D.go to Los Angeles to visit her mom小题4:What is the author's purpose of writing this passage?

A.To express how much she is attached to her home.

B.To declare how much she loves her first house.

C.To describe the state of her family.

D.To look back on her childhood.