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=220 sin100πt（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22 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：D
| 阅读理解。 | ||||||||||||||
schools created more than 100 angels, which are exhibited in the Landers Theater. | ||||||||||||||
| 1. When can you see the play? | ||||||||||||||
| A. At 2:30 p.m. on Thursday. B. At 2:30 p.m. on Saturday. C. At 7:30 p.m. on Friday. D. At 7:30 p.m. on Sunday. | ||||||||||||||
| 2. If your parents take you to see the play, you should pay _____ for the tickets. | ||||||||||||||
| A. $14 B. $20 C. $22 D. $24 | ||||||||||||||
| 3. Which of the following statements is true? | ||||||||||||||
| A. Simon will sing a song in the play. B. You can call 869-1334 to talk to the actors. C. Students will play 100 angels at the theater. D. Students' works will be shown in the theater. | ||||||||||||||
V