A、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1553657102785dddf24531d6c448b95be5f31396595c9image2.png" style="width:108px;height:21px;">
B、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/15536571028541ac665d74e2c401e8f741158f50c1349image3.png" style="width:178px;height:24px;">
C、<img src="https://s3.cn-north-1.amazonaws.com.cn/qingshuxuetang/examination/imgUplod/1553657102898e667a41c74094f55b4f8f2ecbb9057bbimage4.png" style="width:128px;height:21px;">
D、与是否为单位反馈系统有关