A:电动势数值上就等于电源正负极之间的电压
B:所有电源的电动势都是1.5V
C:体积越大的电源,其电动势一定越大
D:不同电源的电动势不同
One day Eddie and Hobo looked at the ____. Eddie thought he saw a____but Hobo thought it was a ____. Because Hobo saw one ____. Eddie thought there were many bright ____and it was too____, so it couldn't be a plane.
用热水器将番茄烫一下,很容易就能撕下一层表皮,这层表皮属于( )
已知平面内动点P与点A(﹣3,0)和点B(3,0)的连线的斜率之积为﹣ 89 .