题干

小组同学利用电压为6V的电源、阻值为15Ω的定值电阻R0,量程为“0~0.6A” 和 “0~3A”的电流表及二氧化锡电阻Rx制作成甲烷气体浓度检测仪,其电路图如图所示。当甲烷气体浓度增大时,电流表的示数将____ (变大/变小/不变)。为使读数更为准确,电流表的量程应选____ 

上一题 下一题 0.0难度 选择题 更新时间:2016-01-06 12:29:23

答案(点此获取答案解析)

变大

,

 0~0.6A

同类题4

阅读理解

B

    Some people like to collect stamps. Others prefer posters or coins. But Pinky Bhutia is different. She collects children. In her mountain village, in Sikkim, she is known as the wonderful young woman who adopts(领养) all the children she can.

    Pinky was 14 when she adopted her first child, a Nepali baby girl, whose patents passed away. Pinky's parents did not mind. Pinky left school and started working full time because she had a baby to feed. Today, she has twelve adopted children, and two sons from her marriage.

    Pinky is about 30 years old and she comes from a common family. If you passed her on the street, you wouldn't give her a second look. She lives in a brown mud-washed(泥刷的) house. There is a vegetable garden outside. Red hens with noisy chicks run all over the garden looking for food.

    If you ask her why she provides a home to so many kids, she smiles shyly. But her eyes are serious. “I know what it is to be poor and hungry.” As a child, her only dream was to eat a full meal, and her favorite amusement was watching people with shoes and imagining what it felt like. By adopting poor and homeless children she is making sure that they never feel that hopeless.

    Pinky feels very proud when she sees her children happy and bright, Her oldest baby, Aarita Rai, is now 20 years old, Then, there is  19-year-old Nimbe who came to Pinky because her mother was unable to look after her. She started to work in a government office two years ago. Ten-year-old Bhim and 14-year-old Kumar came to Pinky five years ago, after their father's death. They started living on a patch of land given by Pinky and grew vegetables for sale.

    “I like children. It's not one more mouth to feed but one more soul saved,” Pinky says.