有一种叫做“压电陶瓷”的电子元件，当对它挤压或拉伸时，它的两端就会形成一定的电压，这种现象称为压电效应。一种燃气打火机，就是应用了该元件的压电效应制成的，只要用大拇指压一下打火机上的按钮，压电陶瓷片就会产生10～20kV的高压，形成火花放电，从而点燃可燃气体。在上述过程中，压电陶瓷片完成的能量转化是[ ]
A．化学能转化为电能
B．内能转化为电能
C．光能转化为内能
D．机械能转化为电能
答案：D
| 阅读理解 China's government has been trying all measures to reduce pollution in the past few years. Now people can enjoy a fresh environment everywhere. The following two graphs are adopted from the column of "City Information" on the webpage of Beijing Review. Graph 1: Olympic Cities Air Quality Report
**API stands for Air Pollution Index(指数). **Particulate matter (PM10) is a major component of air pollution that threatens both our health and our environment. It consists of very small liquid and solid particles floating in the air. **Sulfur dioxide(SO2) acts as an acid．Inhalation(吸入) results in labored breathing, coughing, or a sore throat and may cause permanent lung damage. 1. According to Graph 1, which of the following cities has the worst air pollution? A. Qinhuangdao. B. Tianjin. C. Qingdao D. Shenyang. . 2. If your city is symbolized by either red or purple, the pollution in your city is . A. Moderate or high. B. Moderate or slight. C. Medium or high. D. Medium or slight. 3. Which of the following statements is TURE? A. With API value below 150 the air is free from being polluted. B. The colors from purple to Yellow indicate the air quality is becoming much worse. C. When there are floating solid particles and dust in the air, it is dangerous pollution. D. On September 8th the color-symbol of Beijing City's air quality is 'Blue'. 4. When more citizens are beginning to have labored breathing soon after they are in the open air, it suggests that . A. there is a large amount of sulfur dioxide in the air B. it is so cold that they may have caught a cold C. they are starting to cough or have a fever D. they must be infected with permanent lung disease |