1/Ann's eyes are as brown as John's eyes.
2.Cathy is not as tall as Rose.
3.Linda's hair is as curly as Mary's.
4.Bill is as a good pupil as Tom
5.Your grandparents are not as old as mine.
6.Lisa is not as good at skating as Brenda.
В первом не уверена, т.к. в предложении нет прилагательного, нужного для этой конструкции, поэтому поставила просто brown