下列运算正确的是
A:a2•a3=a6
B:(a4)3=a12
C:(﹣2a)3=﹣6a3
D:a4+a5=a9
Lisa said, “The music ____ (sound) beautiful, doesn't it?”
根据汉语的意思或括号里的词的正确形式完成句子(一空一词,注意词形变化)