A.≤0.2 B.≤0.4 C.≤0.3 D.≤0.1
A.奇數(shù) B.偶數(shù) C.自然數(shù) D.函數(shù)
A.穩(wěn)壓 B.降壓 C.穩(wěn)頻 D.穩(wěn)幅