在公共杆上架设多副VU波段天线时，上下层天线层间距离大于()m，左右间距大于2m。
A.1
B.1.5
C.2
D.2.5
参考答案：B
Erosion that is a slow process, but it constantly changes the features on the surface of the earth.
A．which is
B．although
C．being
D．is
下列哪些药物对乳糖过敏的病人是禁忌（）
A.舒利迭
B.沙丁胺醇
C.信必可都保
D.卡托普利
