分针从12走到4,经过了______分.
5×4=20(分)
故答案为:20.
You needn't have apologized for your absence_______, it' s hardly your fault.
A.besides
B.therefore
C.however
D.meanwhile
超短波的频率范围是()。
A、30~300MHE
B、300~100HME
C、10~50MHE
D、10~100MHE