My grandfather is eighty years old.He always complains about how fast things have changed,and he often says that life used to be better. "Families aren't families the way they used to be."A 1ot of families have broken up.If husband and wife have problems with their _ ,they no longer stay together.And mothers used to stay at home and take  care of their children,but now everyone is busy working.No one has time to 1ook after children at home. And the cars! No one walks any more;more and more people drive.We used to walk five miles to school on schooldays,even in winter.But now we don't.And in school children don't have to think any more.In math class.for example,we used to add,subtract, multiply and divide in our heads.Kids don't use their heads any more;instead,they use calculators . Most families have computers now.In the past we didn't have computers.We didn't even have lights.My mother used to spend all day cooking in the kitchen.But now we don't often eat homecooked food. And people don't talk to each other any more.They are too busy to talk,too busy to eat,to busy to think...   Life used to be simple,but it isn't any more. What has happened these years according to the passage?
Children don't have to think any more in school. Students use calculators in math class. Students used to walk to school,but now they don't. All of the above.