очень надо 4 и 7 поставьте общ/альт/раз/спец во с Did очень надо ​

4. Did my colleague take business letters and translate them into Russian?

Did my colleague translate letters into Russian or Ukrainian?

Did my colleague take business letters and translate them into Russian, didn't he/her?

What language did my colleague translate business letters?

7. Did my friend buy a new mobile telephone at the shopping last week?

Did my friend buy a new mobile telephone or a new MP3 player?

Did my friend buy a new mobile telephone at the shopping last week, didn't he/she?

What did my friend buy at the shopping last week?

все ваши предложения в прошедшем времени,поэтому используем past perfect passive.

they said the medicine had been prescribed by the doctor.

  he understood that the house had been robbed by the thieves.

  she said he had been seen the night before with a pretty girl in the club.

  he said that his walkman had been given to him by his mother as