一天上午.爷爷从花盆里摘下一片紫色的牵牛花.然后把它的颜色擦在一张白纸上,说他会让颜色改变。我不信.爷爷笑了一下,说:“你去拿两支棉签来.等会儿就能变色了。”我半信半疑地找来两支棉签.回来时,见爷爷身旁摆了两碗水。试验开始了,爷爷先拿起一支棉签在其中一只碗里蘸了蘸.然后在涂了花瓣颜色的纸上涂抹,纸上的紫色不见了,变成了红色! One morning, my grandfather took a purple morning glory out of the pot and rubbed its color on a piece of white paper saying he would make the color change. I do not believe. Grandpa laughed and said: “You get two cotton swabs to come .And later will be able to change color.” I half-doubt to find two cotton swabs .When back, see the Grandpa side of the two bowls water. The test began, my grandfather picked up a cotton swab in one of the bowl dipped in dip and then smeared on the paper coated with petal, the paper on the purple disappeared into a red!