It looks like you have a set of sentences that need to be rewritten or completed. Here’s how you might fill in the sentences based on the given prompts:

28. The waiter is serving them dinner now.
→ They are being served dinner by the waiter.

29. The teacher won’t show him the marks.
→ He is not being shown the marks by the teacher.

30. Ken offered Janet a ride.
→ Janet was offered a ride by Ken.

31. Miss Price has taught Arnie a new dance step.
→ Arnie has been taught a new dance step by Miss Price.

32. They should have ordered you a taxi.
→ You should have been ordered a taxi.

These transformations reflect passive voice constructions based on the original sentences.