一、填空题 1.1只苹果的质量约为150___;空气的密度约1.29__;普通保温瓶的容积约2__,灌满水后水的质量约___. 2.人们常说:铁比棉花重,实际是指铁的___比棉花的____.说“铁比棉花重”的条件是________。 3.两个实心正方体铜块,大的边长是小的3倍,则大、小正方体铜块的质量之比是___,密度之比是 First, fill in the blank 1.1 The quality of the apple is about 150___; the density of the air is about 1.29__; the volume of the ordinary thermos is about 2__, the quality of the water after filling the water is about ___ 2. People often say that iron is heavier than cotton, Actually refers to the iron ___ cotton than ____. “” Iron than cotton weight "condition is ________. 3 two solid cube copper, large side length is 3 times smaller, then the mass ratio of large and small square copper block is ___, the density ratio is