复合地基或软弱地基上的设计等级为()的建筑,在施工和使用期间应进行变形测量。
A、甲级
B、乙级
C、丙级
D、丁级
参考答案:A, B
Not only the parents but also their child __________ the Bird’s Nest next week.
A.have visited
B.is going to visit
C.are going to visit
D.have been to
引起邻道干扰的因素有:()
A.滤波器残余
B.倒易混频
C.通道非线性
D.非线性器件饱和,产生非线性失真