①“若x+y=0,则x,y互为相反数”的逆命题是“若x,y互为相反数,则x+y=0”.
②在平面内,F
1、F
2是定点,|F
1F
2|=6,动点M满足||MF
1|-|MF
2||=4,则点M的轨迹是双曲线.
③“在△ABC中,“∠B=60°”是“∠A,∠B,∠C三个角成等差数列”的充要条件.
④“若-3<m<5则方程
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231638043872335/SYS201311012316380438723015_ST/0.png)
是椭圆”.
⑤在四面体OABC中,
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231638043872335/SYS201311012316380438723015_ST/1.png)
,D为BC的中点,E为AD的中点,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231638043872335/SYS201311012316380438723015_ST/2.png)
=
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231638043872335/SYS201311012316380438723015_ST/3.png)
⑥椭圆
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101231638043872335/SYS201311012316380438723015_ST/4.png)
上一点P到一个焦点的距离为5,则P到另一个焦点的距离为5.
其中真命题的序号是:
.
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