B, b  
noun uk/biː/ us/biː/  Bs, B's or b's
  (LETTER)     
  [ C or U ](英语字母表的第二个字母) 
the second letter of the English alphabet
   (MUSIC)      
  [ C or U ]B 调,B 音 
a note in Western music
  Bach's Mass in B minor 巴赫B小调弥撒曲 
   (MARK)      
 [ C or U ](学业成绩、工作表现的)良好,第二等 
a mark in an exam or for a piece of work that shows that your work is good but not excellent
  I was a little disappointed just to be given a B, as I was hoping for an A. 得了“良好”我感到有点沮丧,我一直希望得“优秀”。 
 I got B for physics last term. 上学期我的物理成绩得了“良好”。