A:mooncake
B:train
C:boat
— Are you confident about the English Speech Contest, Sally?— __________. I've got everything ready!
一只黑色的雌兔与一只白色雄兔交配后生了一窝黑兔,则有关控制毛色基因的叙述中正确的是( )
一元二次方程x2-2(3x-2)+(x+1)=0的一般形式是( )