A.λ=1/2c·f B.λ=c/f C.c=1/2λ·f D.c=2λ·f E.f=c·λ
A.1~10MHz B.1.5~10MHz C.2~10MHz D.5~10MHz E.7~10MHz
A.>2000Hz B.>20000Hz C.>200000Hz D.>2000000Hz E.>20000000Hz