Exercise 1. Change the sentences according to the model. Model: We must fulfil complete testing. Complete testing must be fulfilled. 1 . They must expand the line. 2. You could apply for a patent. 3. They should work out the details. 4. I must develop a new trend. 5. We should design a line of clock-television. 6. You should start market research.

1. The line must be expanded by them.2. A patent could be applied for by you.3. The details should be worked out by them.4. A new trend must be developed by me.5. A line of clock-television should be designed by us.6. Market research should be started by you.