临床最常见的外阴恶性肿瘤是（）。
A.恶性黑色素瘤
B.基底细胞癌
C.前庭大腺癌
D.外阴鳞状细胞癌
E.外阴疣状癌
参考答案：D
Knowledge and learning are important if we want to be successful,but they may
also ____ ourthinking. [ ]
A. direct
B. limit
C. change
D. improve
I think pronunciation is than translation. [ ]
A. difficult
B. as difficult as
C. most difficult
D. more difficult
