Frank and Sally (to discuss) these matters for an hour or so. They can’t stop. 24. We (to miss) the bus. Now we’ll have to walk. 25. Don’t come in. I just (to wash) this floor. 26. He (not to stop) eating since he arrived. 27. Scientists (to work out) on the solution to the problem of pollution since early 70’s. 28. He (to be) Minister of Education since 1983. 29. I (to shop) all day and I haven’t a cent left. 30. I (to wait) for an hour. Where is she?

Решение:
1. Frank and Sally (to discuss) these matters for an hour or so. Ответ: Frank and Sally have been discussing these matters for an hour or so.
2. We (to miss) the bus. Now we’ll have to walk. Ответ: We have missed the bus. Now we’ll have to walk.
3. Don’t come in. I just (to wash) this floor. Ответ: Don’t come in. I have just washed this floor.
4. He (not to stop) eating since he arrived. Ответ: He has not stopped eating since he arrived.
5. Scientists (to work out) on the solution to the problem of pollution since early 70’s. Ответ: Scientists have been working out the solution to the problem of pollution since the early 70’s.
6. He (to be) Minister of Education since 1983. Ответ: He has been Minister of Education since 1983.
7. I (to shop) all day and I haven’t a cent left. Ответ: I have been shopping all day and I haven’t a cent left.
8. I (to wait) for an hour. Where is she? Ответ: I have been waiting for an hour. Where is she?