如图13所示,我们用手拉弹簧,它就会伸长;用手压弹簧,它就会缩短.针对影响弹簧的伸长或缩短的因素,请你提出一个猜想,并简述验证猜想的实验方法.(1)猜想: (2)验证猜想的实验方法: 答案:(1)弹簧受到的拉力越大,弹簧的伸长就越大;或弹簧受到的压力越大,弹簧缩短的长度就越大. (2)方法一:①把弹簧固定在铁架台上,用直尺测出弹簧原长L0;②在弹簧下面挂上钩码, 记下钩码重G1,用直尺测出弹簧的长度L1,,得到伸长量△L1=(L1一Lo);③增加挂在弹 簧下面的钩码数量,The
journey around the world took the old sailor nine months, the
sailing time was 226 days.
A.
of
which
B. during which
C. from which
D. for which