浅表性胃窦炎胃镜下可见错误的是
A.病变多呈弥漫性B.粘膜呈红白相间或花斑状C.粘液分泌增多D.表面常覆盖白色渗出液E.粘膜皱襞变平或变细
参考答案:E
He devoted most of his time to his research, believing his hard work would___sooner or later.
A.put off
B.take off
C.come off
D.pay off
扩频通信包括()
A、跳频扩频
B、三角波能量扩散
C、FH/DS混合扩频
D、直接序列扩频