1 They have to paint the house.
The house has to be painted by them.
2 Catherine will clean the garage on Saturday.
The garage will be cleaned by Catherine on Saturday.
3. The students in Miss Marple's class can't solve the Maths problems.
The Maths problems can't be solved by the students in Miss Marple's class.
4. The police are going to send the robber to prison.
The robber is going to be sent to prison (by the police).
5. Someone should take out the rubbish.
The rubbish should be taken out.
6. The security guard has arrested the thief.
The thief has been arrested by the security guard.
7. You mustn't throw rubbish on the ground.
Rubbish mustn't be thrown on the ground.
8. A famous reporter might interview Maggie.
Maggie might be interviewed by a famous reporter.
9. They may sell their house to the Adams.
Their house may be sold by them to the Adams.
1 a) I'm doing my homework, (ii) so I can't come to the party with you.
В главной части форма глагола Present Continuous указывает на то, что действие выполняется в момент речи - это причина, почему говорящий не может пойти на вечеринку.
b) I do my homework (i) on the bus most days.
Present Simple в главной части в сочетании с most days обозначает регулярно совершаемое действие.
2 a) I'm not enjoying this film - (i) can we watch the other DVD?
речь о конкретном фильме, который смотрят в момент речи.
b) I don't enjoy films - ( ii) I prefer reading.
Формы Present Simple в обеих частях используются для описания предпочтений (то есть характеризуют) говорящего.
3 a) I'm looking for (ii) Maria. Have you seen her?
Говорящий ищет Марию в момент речи.
b) I look for (i) new artists. It's an interesting job.
Форма Present Simple глагола look указывает на обычно совершаемое действие (человек говорит о своей работе)
4 a) I'm standing (ii) on the bridge. I can see you!...
Ситуация происходит в момент речи.
b) I stand (i) on the bridge every day and watch the boats.
Present Simple глагола stand + слова every day указывают на привычку/регулярное действие
5 a) The train is arriving (ii) in London now. See you in 5 minutes.
Конкретная ситуация, действие происходит в момент речи.
b) The train arrives (i) late sometimes.
Sometimes - маркер Present Simple.
6 a) Are you using (i) this pen? No? OK, I'll use it for a moment.
Вопрос про конкретную ручку в момент речи. => Present Continuous
b) Do you use (ii) a pen and paper or do you do everything on the computer?
Вопрос про обычно совершаемое действие.