多源性房性心动过速表现为（）
A.P波形态多样
B.V1导联P波高耸
C.仅在V1导联有深倒的P波
D.P波存在但被掩盖
E.无P波
参考答案：A
—Do you think I should accept his invitation, Jim?
—________If I were you, I certainly would.
A．None of your business.
B．It depends.
C．Why not?
D．I don’t think so.
互见中，帆船在航时，应给下列（）种船舶让路。
A.从事捕鱼的船舶
B.操限船
C.失控船
D.以上均是
