12.
1. When did father promise to buy Mike a bicycle? He promise to buy Mike a bicycle at half past 12. 2. When did Nick promise the teacher to work hard? Nick promise the teacher to work hard last Monday. 3. When did Nina promise to invite all her friends? Nina promised to invite all her friends two days ago. 4. When did Tom's grandfather promise the boy to give him his gold watch? Tom's grandfather promised the boy to give him his gold watch yesterday. 5. When did she promise to buy a new coat for her mother? She promised to buy a new coat for her mother at 5 o'clock.
13.
1. Why did Nick refuse to answer this question? I think, Nick refused to answer this question, because he didn't know the answer. 2. Why did she refuse to marry him? I think, she refused to marry him, because she doesn't love him. 3. Why does mother refuse to give Bob money? I think, mother refuses to give Bob money, because he spends money very fast. 4. Why did driver refuse to take children with him? I think, driver refused to take children with him, because they had to go to school. 5. Why did the English postmen refuse to work? I think, the English postmen refused to work, becaise they were tired. 6. Why do Mike and Pete often quarrel? I think, Mike and Pete often quarrel, because they are very different people. 7. Why is Zina sad today? I think, Zina is sad today, because she got "two". 8. Why do you like these merry boys? I like these merry boys, because they tell jokes very well.