Lesson 4 Versión en línea Look, read and answer. por Edith Alvarez 1 Add ed / open Written answer 2 Add ing / open Written answer 3 Add ed / happen Written answer 4 Add ing / happen Written answer 5 Add ed / chase Written answer 6 Add ing / chase Written answer 7 Add ed / dance Written answer 8 Add ing / dance Written answer 9 Add ed / worry Written answer 10 Add ing / worry Written answer 11 Add ed / study Written answer 12 Add ing / study Written answer 13 Add ed / stop Written answer 14 Add ing / stop Written answer 15 Add ed / rob Written answer 16 Add ing / rob Written answer