A.軟時(shí)鐘 B.硬時(shí)鐘 C.晶振 D.電子計(jì)數(shù)器
A.2.5MΩ B.500MΩ C.100MΩ D.1000MΩ
A.5~10s B.0~10s C.30s D.10~20s