问题
选择题
— ____ do you study for a test? — I study by listening to tapes |
A. What B. Why C. How D. When |
答案
答案:C
— ____ do you study for a test? — I study by listening to tapes |
A. What B. Why C. How D. When |
答案:C
一个电热水器的铭牌如表所示,请根据铭牌所提供的信息计算:
额定电压 频率 额定功率 温控范围 内胆容积 内胆额定压强 | 220V 50Hz(赫兹) 2000W 20~80℃ 40L(升) 0.8MPa(兆帕) |
②正常工作时,上述加热过程需通电多少时间?