龙骨与牡蛎的共同功效是()
A.平肝潜阳,清肝明目
B.平肝潜阳,纳气平喘
C.平肝潜阳,软坚散结
D.平肝潜阳,收敛固涩
E.平肝潜阳,清热利尿
参考答案:D
频域的相对稳定性常用相角裕度和()表示,工程上常用这里两个量来估算系统的时域性能指标。
—The rescue team are considering ______they can do more for the people suffering from the snow storm.
—So they are.
A.what
B.whatever
C.if
D.how