Liu Tao: What's the time now, Yang Ling?

Yang Ling: It's four thirty. It's time to go home.

Liu Tao: It's raining(下雨).Where is my umbrella?

Yang Ling:Look!There's a red umbrella under the desk.

Liu Tao:That isn't my umbrella.

Yang Ling:There are four umbrellas near the blackboard. Which one is yours（你的），Liu Tao?

Liu Tao:The blue one. Thank you, Yang Ling.

Yang Ling:Shall we go home together？

Liu Tao:Great!Let's go.

多项式x²＋y²、－x²＋y²、－x²－y²、x²＋（－y²）、8x²－y²、（y－x）³＋（x－y）、2x²－$\frac{1}{2}$y²中，能在有理数范围内用平方差公式分解的有（   ）