手术需扩大淋巴结引流方向切除范围的是（）

A.鳞状细胞癌

B.基底细胞癌

C.恶性黑色素瘤

D.以上都是

E.以上都不是

.People have planted a great many trees in order to _____ wind and sand in the desert.

A．hold down

B．hold up

C．hold back

D．hold out