某工厂有两台同样的机器，一台连续工作，另一台间断性地工作。针_爱下问搜题

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问题单项选择题

某工厂有两台同样的机器，一台连续工作，另一台间断性地工作。针对这种声波起伏或不连续的评价参量为（）。

A.等效连续A声级

B.累积百分数声级

C.昼夜等效声级

D.感觉噪声级

答案

参考答案：A

多选题

在同一水平面上有A、B两物体，相距s=7m，A在后B在前，A以v_A=4m/s 向右作匀速直线运动，此时B的瞬时速度为v_B=10m/s，方向也向右，且以加速度a=2m/s²作匀减速直线运动到停止运动．从此位置开始计时，A追上B所需时间为（　　）

A．7s

B．8s

C．9s

D．10s

填空题

Surprise we do bad until friend so　 Good say happy know after

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