Составьте 3 предложения present simple. 3 предложения present continuous 3 предложения present perfect

1I buy new computer;ussual i write e-mail my mother at this time;she does her housework
2she is sitting at home;i am doing my homework; he is writting an e-mail
3i haven't written my homework yet;she has bought new shorts recently;he hasn't worked for a month