A、稳定<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15510832221782a32892016124539b750e9c2abdc2910image1.png"style="width:19px;height:24px;"/>
B、放大信号
C、抑制零点漂移
D、增大<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/155108322228983feeb501c1944cfad6efa45f770b671image2.png"style="width:17px;height:24px;"/>