问题
选择题
The young pianist is very excited because the concert given by him has never been ____ .
A．successful
B．more successful
C．most successful
D．the most successful
答案
答案：B
比较级用于否定句表达最高级含义。 句意：年轻的钢琴家非常激动因为他的音乐会从未如此成功。
，场强
电荷从A点移到B点电场力做了负功
电荷分别放在A、B两点时具有的电势能