石决明具有的功效是
A.平肝潜阳,软坚散结
B.平肝熄风,镇惊安神
C.平肝潜阳,清肝明目
D.平肝熄风,祛风止痛
E.熄风止痉,润肠通便
参考答案:C
You should have told me there was no meeting today, I ___ have run all the way here through the heavy rain.
A.can’t
B.mustn’t
C.shouldn’t
D.needn’t
对于限峰值功率的N维连续信源,当概率密度()时连续信源熵具有最大值。