Ответ:
1) They will go to the party, If they are invited. (они пойдут на вечеринку, если их пригласят)
She will stay in London, if she gets a job. (она остановится в Лондоне, если она найдёт работу)
I will buy a new dress, if I have enough money. (Я куплю новое платье, если у меня будут лишние деньги)
2) A test is written by children. (Тест был написан детьми)
A milk is bought by mother. (Молоко было куплено мамой)
London will be visited by students. (Лондон будет посещён студентами)
Homework is given by teacher every day. (Домашнее задание даётся учителям каждый день)
3) I would to speak about my future job. I think, I want to get a job as a programmer, because they have a lot of money and this is so comfortable. I need to pass computer science and physics for this profession. I can also pass English. You need to be able to use computers and know the programs.This profession is very popular and highly paid. My family will be proud of me!