Когда на территорию Беларуси проникли индоевропейцы

1) Who is this girl? - She's my sister. - Who she is (what it does)? - She is an economist! 2) as polar speak German?-She knows it very well .3) when your son is preparing lessons? - Vecherom.4) learns how your son? - He learns very horosho.5) you do not know these words , repeat these words again and grammar rules home .6) of you who economist? - petrov.7) which of you is a good student? - anna