A:开关闭合后,甲图中L1灯更亮,乙图中L2灯更亮
B:甲图中开关闭合后,L1灯、L2灯发光时的电功率之比为38:25
C:开关闭合后,通过比较灯泡的亮暗来判断电功大小,再通过电流表和电压表示数说明影响电功大小的因素
D:乙图中开关闭合后,首先是调节滑动变阻器,使L2灯电流为0.3A,再看L1灯电流并比较L1、灯L2灯的亮度
Schools of Nangtong, Jiangsu Province start the morning classes an hour later than before. That's, they begin the first class at about 8:30 a.m. This helps students feel less tired. The students are happy about the change. Liu Ming said,“I'm glad that we don't have to get up so early.” Wu Hongli feels the same. She said that would be good for her health. “I used to get up at 6:30 a.m. I had to drink coffee every night, or I would feel too sleepy to finish my homework, ” said Wu. Many teachers agree that the change helps students learn better. “Students used to doze(打瞌睡) in the first two classes in the morning,” said Huang Shan, an English teacher. “But now they are full of energy in class and learn much better than before.” However, some parents are worried that more sleep means less learning. There used to be five classes in the morning. Now there are only four.In fact, every coin has two sides. So does the change in the school timetable.根据短文内容,判断下列句子正误,正确的涂“A”,错误的涂“B”。____ Schools of Nantong used to begin the first class at about 7:30a.m.____ Some students and parents feel worried about the change in the school timetable.____ Wu Hongli enjoys drinking coffee at night.____ The English teacher thinks the new timetable does good to the students’ study.____ “Every coin has two sides” means “凡事皆有利弊” in Chinese.
下列关于被子植物和人体运输结构和运输动力的叙述,错误的是( )
一元二次方程想x(x-2)=0根的情况是( )
某轮船2009年9月1日10时自西十二区进入东十二区,则此时船上的日期应为2009年的( )
某实验室的废液中,可能含有CuCl2、NaCl、Na2SO4、Na2CO3、Ba(NO3)2中的一种或多种.某同学取该废液观察为无色溶液,向其中滴加BaCl2溶液产生白色沉淀,继续滴加稀硝酸无明显现象.根据以上实验现象分析,下列推断正确的是( )