Choose the right form of the verb to complete the sentences. 1. your homework? – no, i forgot the hometask. a) have you been doing b) have you done 2. i her for a long time. a) have known b) have been knowing 3. my sister english for several years but she can’t speak it. a) has learnt b) has been learning 4. my little brother that santa claus doesn’t exist. a) has just discovered b) has been just discovering