Решение:
1. The pupils have opened their books, but they have not read the text.
2. Kerim has watched the movie, but John has not come.
3. It has rained there, but it has not snowed.
4. We have started writing a test, but we have not finished it.
5. She has phoned me, but I have not answered her call.
6. The teacher has read the text, but we have not.