A:makes its breath
B:takes its breath
C:holds its breath
D:lets its breath
of us has to have our temperature taken when we get in school every morning.
在△ABC中,AB=1,AC=3,D是BC边的中点,则AD→·BC→= ( )
弹簧受到的拉力F/N
0
2
4
6
8
10
12
弹簧长度L/cm
3
5
7
8.5
分析实验数据可以得出的结论是____
该同学制作的弹簧测力计的量程是____ N,弹簧的原长是____cm.
1图 2图