Final answer:
The given sentences have been transformed into the passive voice.
Step-by-step explanation:
The sentences after being turned into passive voice are as follows:
- The house was painted by John last Saturday.
- The ballpoint pen was invented by the Biro brothers.
- The answers are being written by Billy now.
- Two books were read by Alice.
- English is spoken very well by them.
- The cells are implanted in the body by them.
- Chemical engineers are attracted by tissue engineering.
- A chest was grown in a lab by a team of American scientists.
- Patients will be monitored by doctors.
- Slow computers were used by researchers.