为什么This pen is easy to write with.可以变成This is an easy pen to write with?

为什么This pen is easy to write with.可以变成This is an easy pen to write with? This is yours pen.为什么? What is this 是This is a pen.还是.It is a pen?为什么? this is our pen---------------- This pen is beautiful? This pen is yours this food is easy to digest,能否说this food to digest is easy.为什么 this is an easy it is easy for me to( )which pen is mine.为什么填say it is easy for me to( )which pen is mine.选择：tell say speak talk为什么 为什么说This is my a pen是错的? 为什么不能说 This is my a pen this is ------- -------- （pen).There are -------- (pen).填空 i think the pen is easy to write是否正确,请检查一下为什么, what's this?It's a pen.为什么不能说是this is a pen.我们老师说就是不能说this is a pen.为什么 is this your pen? 为什么答案上面是 yes this is 怎么不用yes it is ... Is this your pen Is this his pen?选择疑问句 This is pen变复数