10. Read and translate. Which sentences express suggestion? Which sentences express strong obligation?:

1) You should go on a diet. 2) Your diving equipment must be cleaned regularly if you want to keep it in good condition. 3) You should share your problem with your parents. 4) You must fasten the belts in a plane. 5) I am to do this exercise, because my instructor told me to do it in order to check my progress on the unit.

11. Fill the gaps, using modal verbs must, should, need, have to, (to) be to, may, can. Open the brackets and put the verbs into the correct form:

1) As we have agreed before, we _____ (to meet) at two o’clock to go to the planetarium to observe the planetary motion through the huge telescope. 2. Who _____ (to go) to the library to get the new books? – I _____, but I can’t because I ______ (to finish) an important work at the laboratory. 3. You ______ (to attend) a very interesting lecture which (to be held) tomorrow. 4. If you want to improve your English, you _____ (to work) hard. 5. The computer isn't working. They_____ (to damage) it during production. 6. The book is optional. The professor said we _____ (to read) it if we needed extra credit. But we _____ (to read) it if we don't want to. 7. They _____ (to deliver) package tomorrow afternoon. It was sent by express mail this morning. 8. If you want to get a better feeling for how the city is laid out, you ____ (to walk) downtown and explore the waterfront. 9. He _____ (to be) careful with this device. It is very dangerous. 10. I ______ (to speak) Arabic fluently when I was a child and we lived in Egypt. But after we moved back to Canada, I had very little exposure to the language and forgot almost everything I knew as a child. Now, I _____ just (to say) a few things in the language. 11. It _____ (to be) Sam who called and didn't leave a message on the answering machine. He said he wanted to get together with us this weekend. 12. There is something wrong with your TV. You ____ (to call) a repair-man.

12. Read and translate. Pay attention to the usage of the modal verbs and their equivalents. Then work with a partner. Take turns to ask and answer questions to these paragraphs. Use the words and word combinations below:

important role computer mistakes

educational and entertaining computer-made catastrophe

basic computer skills bugs

to gain access to prevent a crash

1. Computers play an important role nowadays. Employees can work faster at their workplace then they used to in the past; in addition to this, computers can be educational and entertaining. 2. From a very young age children can gain basic computer skills through programs that allow them to learn, draw, paint, and play. In the future, these skills can help them gain access to the enormous versatility of the cultural heritage of the humanity.

3. As the demands placed on computers grow, so has the number of incidents involving computer mistakes. We should not ignore the warning from computer experts about the possible occurrence of a computer-made catastrophe. ‘Safety critical’ systems (системы обеспечения безопасности), that fly planes, drive trains or control nuclear stations also may have bugs (the word bug means ‘mistake’).

The only solution is that the IT experts have to learn to think clearly and to be able to demonstrate mathematically that the program cannot go seriously wrong.

Computerized systems may fail to warn of impending disaster (надвигающаяся катастрофа, опасность) and it is only quick human reaction that prevents a crash.