题干

创建生态文明城市需要我们共同关注环境.我市某兴趣小组为了检测空气质量指数,设计了如图甲所示的检测电路,R为气敏电阻,其电阻的倒数与空气质量指数的关系如图乙所示,己知电源电压12V保持不变.R0=5Ω,当电压表示数为4V时.求:

上一题 下一题 0.0难度 选择题 更新时间:2018-12-09 01:11:57

答案(点此获取答案解析)

同类题4

完形填空
    As a teenager, I am often asked what I am going to be in the future. A lawyer? A doctor? Or a scientist? No, my ideal career is to be a teacher. One of the 1for that is I want to be a teacher like Mr. Chen.
    "Look! Do you know what it is? A-ha, it's the  2 ! And it will always move around the sun."Mr. Chen said and pointed to his head. He then touched the nose and 3 , "Can you tell me the name of this mountain? It is the highest mountain on Earth! What's the  4of it? Yes, it's 8844.43 metres…" I'll never forget my first geography lesson. He was  5 humorous that we all fell in love with his lessons   6. It's Mr. Chen who opened the door of geography for us.
    Generally speaking, most of the teachers are strict7students and sometimes a little bit demanding(苛求的), not so with Mr. Chen. He is a lighthouse, showing us the way to the treasure of knowledge. He is a friend and easy to get  8 with, always encouraging us to speak out loud without 9our shyness and other disadvantages. He is an example, volunteering his time to students and other teachers.
     One day I happened to meet him in the hospital. Seeing the cut on his arm, I realized he was donating his 10. I was moved and was  11 another lesson, a lesson of love and devotion.
    Every time I see my globe(地球仪), it would 12me of Mr. Chen. He is the most unforgettable teacher I have 13met and he will always be. Someday I hope I am  14  to be a teacher like him.
    Thank you, Mr Chen, thank you for making learning not a job but a joy.
    Thank you for helping me to discover what I do best and to do it even  15Thank you for understanding all of us and giving us the time and care each of us needs.