Помогите я прошу помогите пожалуйста! Use the present Perfect continuous and

Помогите я прошу помогите пожалуйста! Use the present Perfect continuous and for or since for each of the following situations. Пример: My friend started reading an interesting book a month ago.He is still reading it. He has been reading the book since last month. 1.Dmitry started playing chess when he was 10 and he is still playing it. ..........................................................since he was 10. 2.Victor began writing a letter to his pen-friend in the U.K. last week and he is still writing it. ................................................since he last week.