如图所示，理想变压器原副线圈匝数之比为4：1，原线圈接入一电压为u=220sin
题型：多选题
问题：
如图所示，理想变压器原副线圈匝数之比为4：1，原线圈接入一电压为u=220 sin100πtV的交流电源，副线圈接一个R=27.5Ω的负载电阻．则下述结论正确的是（ ）A．副线圈中电压表的读数为55V B．副线圈中输出交流电的周期为0.01s C．原线圈中电流表的读数为0.5A D．原线圈中的输入功率为110  |
W题型：多选题
"Can I see my baby?" the happy new mother asked. When the baby was lying in her arms and she moved the cloth to look upon his tiny face, she gasped(吃力地喘着气). The doctor turned quickly and looked out of the hospital window. The baby had been born without ears. Luckily, time proved that the baby's hearing was perfect. Though the misfortune(不幸)happened to him, he grew into a handsome boy. Yet he felt ashamed when he communicated with others.
“You should get in touch with other young people,” his mother told him, with a kindness in her heart. The boy’s father talked with the family doctor about his ears. “Could nothing be done?” the father asked. “I believe I could give him a pair of outer ears, if they could be got,” the doctor replied.
Two years went by. One day, his father said to the son, “You are going to the hospital, Son. Mother and I have someone who will donate the ears you need, but it’s a secret.” The operation is a big success. Later he married and entered the diplomatic(外交的)service. One day, he asked his father, “Who gave the ears? Who gave me so much? I could never do enough for him or her.”
“You could, my son,” said the father, “but the agreement was that you are not to know…not yet.”
The years kept their secret, but one of the darkest days did come. He stood with his father over his mother’s casket(棺材). Slowly, the father stretched forth(伸出) a hand
and raised the thick, reddish brown hair to reveal the mother had no outer ears.
"Mother said she was glad she never let her hair be cut," his father whispered gently, "and nobody ever thought mother less beautiful, did they?"
小题1:Why did Mother gasp when she saw her newborn baby?
A．Because her son had a tiny face.
B．Because she saw her son crying.
C．Because her son was in her arms.
D．Because her son was born imperfect.小题2:Who gave the son the ears?
A．His mother.
B．His father.
C．A doctor.
D．A stranger.小题3:The underlined word “reveal” in the last but one paragraph means “________”．
A．see
B．show
C．find
D．search小题4:The best title for the passage would be ________.
A．Mother’s hair
B．An unforgettable memory
C．Who gave me the ears?
D．Who is my best respectable person?小题5:The main purpose of the passage is to tell readers that ________.
A．The secret was kept until the mother died.
B．Real love lies in what is done but not known.
C．The operation on the boy was a great success.
D．The boy entered the diplomatic service when he grew up.