h/cm
2
4
6
8
10
12
F/N
2.4
2.0
1.6
1.4
2016年3月5日,面对台湾因历史和显示原因而变动的局势,***划定了三条底线,即道路底线、政治底线和主权底线。其中主权底线是( )
- These problems are too hard to . Will you give me some advice?
- There are many ways. The most important is to have a careful plan.
如图,在Rt△ABC中,∠ACB=90°,∠ABC=60°,BC=4,E是AB边的中点,F是AC边的中点。则EF=____。