题型:填空题 I really can’t decide _____ first. A small computer or a big one?A.what to buy B.to buy whatC.which to buyD.to buy which 查看答案
题型:填空题 一根轻质弹簧,当它在100N的拉力作用下,总长度为0.55m.当它在300N的拉力下,总长度为0.65m,求:(1)弹簧不受拉力时自然长度为多大?(2)此弹簧弹性系数多大?(提示:F=k△x中,k为弹性系数) 查看答案