Change the following sentences using the past tense form of the modal verb: 1. It must be born in mine that he quickly forgets his promises. 2. Those who cannot read or write have to remember things. 3. We must discuss this problem in detail. 4. A machine can do work which man is unable to do. 5. Every scientist must check the results of his research. 6. The boy tries hard, but he cannon act on the stage. 7. We must do as we are told. 8. The available data is not sufficient, but we must come to a decision.

21. He has been watching TV since morning. (Present Perfect Continuous.)

22. Tomorrow I am having an English class at 8 o'clock.(Present Continuous)

23. The air in the city is becoming more and more polluted. (Present Continuous)

24. I've lost my purse. (Present Perfect)

25. Her hair is dirty. She has been painting the house the whole day long.

(Present Perfect Continuous.)

26. You are always losing something! (Present Continuous)

27. You have already been  writing the composition for two hours. (Present Perfect Continuous).

Dear Mary,
How are you? I had a wonderful time last weekend.
I went to the seaside with my friends. We
traveled there
by bus. We
  couldn`t find any rooms to rent, so we

stayed in a hotel with a nice view of the see.
On Saturday w e spent all day on the beach. It was a little cold, so we
didn`t swim in the sea. We were just sitting on the sand and
watching the sea. Then w e had dinner in a cafe. I ate fish and chips. In the evening w e went to the cinema, but I didn`t like the film very much.
On Sunday we visited a local museum. Then we walked
along the river and took some pictures before we

caught the 5 o’clock bus back.

I enjoyed my weekend very much.
I hope your weekend was great, too.
Write soon.
Love,
Jackie.