books.google.com - The twins have an awesome new roller coaster in their backyard. It was a surprise gift from their new friend Billy. Jessica and ELizabeth invite all their friends from school to come ride it. But the twins didn't expect everyone at Sweet Valley Elementary School to show up! Soon the Wakefields' backyard...http://books.google.com/books/about/A_Roller_Coaster_for_the_Twins.html?id=Q-zLEkAkkvUC&utm_source=gb-gplus-shareA Roller Coaster for the Twins!