声散射
参考答案:
当声波遇到障碍物时,部分波会偏离原来路径,从而造成声场变化,成为声散射。实际的波与假设障碍物不存在时所应出现不受干扰的波之间的差定义为散射波
With everything needed_____, Mrs. Jackson went to the supermarket after work in a hurry.
A.buying
B.to buy
C.bought
D.Buy
终末血尿提示病变部位在
A.后 * * 或膀胱颈部B.前 * * C.肾D.输尿管E.膀胱