突触后抑制
参考答案：
是指通过抑制性中间神经元末梢释放抑制性递质，使与其发生突触联系的神经元产生抑制性突触后电位而发生的抑制。
缺失牙为，按照Kennedy分类法应属于（）
A.Kennedy第一类
B.Kennedy第二类
C.Kennedy第三类
D.Kennedy第四类
One of the main responsibilities of ICMP is to report （1）. Although technology has produced increasingly reliable transmission media, errors still exist and must be handled. IP is an （2）protocol. This means that error checking and error control are not a concem ofIP JCMP wasdesigned, in part, to compensate for this shortcoming. Howerver, ICMP does not （3）errors, itsimply reports them. Error correction is left to the higher-level protocols. Error messages arealways sent to the original（4） because the only information available in the datagram aboutthe route is the source and destination 1P addresses. ICMP uses the source IP address to send theerror massage to the source of the （5）
（2）是（）
A.reliable
B.unreliable
C.available
D.Unavailable
，按照Kennedy分类法应属于（）