乳腺癌淋巴结转移首先应在何部位（）
A、锁骨上
B、腋窝
C、内乳
D、肺
E、骨
参考答案：B
方程3x2-2x=1的二次项系数，一次项系数，常数项分别是______．
Having checked the doors were closed, and______all the lights were off,the boy opened the door
to his bedroom.[ ]
A. why
B. that
C. when
D. where
