Miss Smith, an American lady, has taught English for three years.
A:we
B:us
C:our
54-(18+29)=( )
袋中装有大小一样的白球和黑球各3个,从中任取2个球,则两个均为黑球的概率是( )
炒菜时,如果不慎将食盐或食盐水溅到火焰上,看到的现象是____ ,其原因是____ .