脉冲多普勒检测卵巢恶性肿瘤流速曲线特点多为（）。
A.中速中阻
B.高速高阻
C.低速高阻
D.低速低阻
E.高速低阻
参考答案：E
— How is your friend coming?
— I'm not sure. He ______ drive here. [ ]
A. may
B. can
C. must
D. will
连值班员由连长轮流担任，受营首长领导。
