Matching Pairs KB15 Use of soOnline version Use of so. Kid's Box 4 Unit 5 Activity Book by Valeria Itzel Herrera Díaz 1 We couldn't find our books so 2 She couldn't find her glasses so 3 He couldn't find his pen so 4 She couldn't find her phone so 5 I couldn't find my camera so 6 He couldn't find his coat so she couldn't read her book. he had to write with a pencil he had to wear a jacket I couldn't take any photos. we didn't do our homework. she couldn't talk to her friend.