乳腺癌患者乳腺皮肤出现“酒窝征”的原因是（）。

A.肿瘤侵犯了胸大肌

B.肿瘤侵犯了Cooper韧带

C.瘤细胞堵塞了局部皮下淋巴管

D.肿瘤侵犯了周围腺体

E.肿瘤侵犯了局部皮肤

When the cooking class changed to Tuesday，I had to_________so that I could________my

daughter from her piano lessons.[ ]

A．drop in；pick up  

B．drop off；pick up

C．drop out；pick up  

D．drop by；pick out