【简答题】在“验证力的平行四边形定则”实验中,需要将橡皮筋的一端固定在水平木板上,另一端系上两根细绳,细绳的另一端都有绳套.实验中需用两个弹簧秤分别钩住绳套,并互成角度地拉橡皮筋. (1) 某同学认为,为了减小实验误差,在此过程中必须注意以下几项,其中正确的是 ________( 填入相应的字母 ) . A .两根细绳要尽量短一些 B .弹簧秤的拉力应适当的大一些,但不要超出量程 C .橡皮筋应沿两绳夹角的...
【简答题】He is as a leader but he hasn’t in teaching. A.success many experiences B. asuccess much experience C. greatsuccess an experience D. agreat success a lot of experiences