美国最大的商业中心和港口是（）
A．纽约
B．波士顿
C．华盛顿
D．芝加哥
参考答案：A
乳癌病人局部皮肤出现"酒窝征"的原因是（）
A.粘连
B.肿物压迫
C.并发炎症
D.癌肿侵及Cooper韧带
E.癌细胞堵塞表浅淋巴管
My elder sister is _______ studying in Britain and she can speak English quite fluently like
a native speaker. [ ]
A. in the present
B. at present
C. at the present
D. for the present
