1.This is my ring.(改为一般疑问句)（ Is ）（this ）（your ）ring?
2.It is a clock.(改为否定句）- It 【 is not 】a clock.
3.Are those her notebooks?(改为单数句）（ Is ）（ that ）（ her ）（ notebook ）?
4.That is a green pencil.It's Mike's.（合并为一句）（ The ）green pencil is( Mike's ).
祝你学习进步,更上一层楼! (*^__^*)
不明白的再问哟,请及时采纳,多谢!