She a student ten years ago, but she a teacher now.
A. is; was
B. was; is
C. was; was
答案:B
Ⅲ度烧伤创面的特点为()
A.皮肤红斑、烧灼感
B.皮肤红肿、疼痛、有水泡
C.创面有水泡、痛觉迟钝
D.无水泡、痛觉消失
E.痂下有树枝状栓塞血管
利用状态极限概率和状态一步转移概率来求m阶马尔可夫信源的极限熵。