【简答题】点K(m,n)在坐标平面内,若mn>0,则点K位于______象限;若mn<0,则点K不在______象限.
【简答题】The thief ________away before the police ________. A. ran, arrived B. had run, had arrived C. had run, arrived D. ran, had arrived
【判断题】制造业和服务业选址的依据和偏重点不同,制造业更多关注成本
【简答题】在 中, , .若点 满足 ,则 ____________,
【判断题】焊接结构工艺性一般包括焊接结构材料选择、焊接方法、焊缝布置和焊头设计等方面内容。 ( )
【简答题】已知点P(2a+2,a-3),若点P在x轴上,则a=______;若点P在y轴上,则a=______.
【简答题】已知⊙O的半径为5,若PO=5.5,则点P在______;若PO=4,则点P在______.