15 They said they would go to the beach if the weather was nice the day after (loại 1)
16 I told Mike Halen would know what to do if she were late (2)
17 Mark said he would have spoken to Frank if he had seen him the day before (3)
18 The girl said he wouldn't run away if she saw a spider (2)
19 David told her if she had too much to do, she could ask him to help her (2)
20 He told me if I studied harder, I would get high marks in next exam (1)