переведите предложения обращая внимание на согласование времен
1  I did not know that my friend's son had failed in chemistry.
2 They thought I could drive a car
3 The boy said he had scarcely enough money to return home.
4 I knew he was experimenting for hours.
5 They said that chosen their course and nothing could turn them from it.
6 We considered that she had already obtained her Master's degree in mathematics.
7 The student said that he could not translate the article without a dictionary.
8 I did not think that she would be refused a better room for her research. 
9 He asks if he may keep this book as long as he needs it.
10 They told the child that the weather was fine and he could have a walk for two hours.
11 He asked how normal temperature was maintained in the underground.
12 He asked whether in the early days the trains had been driven by locomotives which burnt coal.
13 He said that entirely automatic driving would be developed.