用石蕊染成紫色的干燥纸花，进行如下操作，能够观察到纸花变红的是____ ．
She is a talented singer a good actress.
I don't know _______ or not the film is suitable for children.
医疗上用的生理盐水是0.9%的氯化钠溶液．要配制0.9%的氯化钠溶液100g．其中选用仪器或操作正确的是（ ）
