超声波法检测的适用范围是什么?
参考答案:
适用于已预埋声测管的混凝土灌注桩桩身完整性检测,判定桩身缺陷的程度并确定其位臵。
阅读对话,填写单词。
Li Ming: 1.____ you usually go home by bus?
Jenny: Yes, but sometimes I 2.____ my bicycle.
Li Ming: Do you 3._____?
Jenny: No, I never walk. I live too 4.____ from school. How about you?
Li Ming: l go home on 5._____.
已知直线l1:mx+8y+n=0,l2:2x+my-1=0,分别满足下列情况:
(1)两条直线相较于点P(m,-1);
(2)两直线平行;
(3)两直线垂直,且l1在y轴上的截距为-1,试分别确定m,n的值.