1. You (may/ought to/are to) take care of your parents. 2. My sight is getting worse. Next year, I’m afraid I (cannot/may not/won’t be able to) read without glasses. 3. Twelve delegates from several countries (can/have to/are to) meet at the end of February. 4. Excuse me, (could/may/must) you tell me the way to the Houses of Parliament? 5. The weather is getting worse. It (must/is likely/may) rain. 6. There are no people in the hall, we (must/can/need) have a talk there. 7. Although he felt ill, he (could/was able to/may) finish all the paperwork. 8. You (can/must/ought to) go and see that movie. It’s very interesting. 9. Don’t worry, you (don’t have to/mustn’t/may not) pay now.10 When we were at school, we (had to/ought to/must) wear a uniform.
Ex. 16. Give the proper English equivalents for the Russian expressions.
1. Нам пришлось perform the operation of addition to find the answer. 2. Ему предстоит specify the conditions of the experiment. 3. Им разрешают use a dictionary if necessary. 4. Я в состоянии solve this difficult problem myself. 5. Вам следует remember that multiplication is associative. 6. Ей не надо use this theorem. 7. Они могут apply their theories in practice. 8. Вы обязаны remember several rules about division. 9. Можно мне start the calculations now? 10. Вам следует to accept everything your parents say as an axiom.
Ex. 17. Translate from English into Russian.
1. Everyone studying mathematics must have a good understanding of the meaning of each symbol. 2. These expressions may contain numbers and letters. 3. Multiplication can be distributed over addition, e.g. 14x12 = (14x10)+(14x2) 4. A prime number is a number that can be divided evenly by only 1 and itself. 5. No multiplication sign is to be used between two letters or a letter and a number written side by side. 6. The plus sign should be understood when there is no sign before the number. 7. Will you be able to name other factors of 18 except nine and two? 8. In some cases, when we have to name a whole number in a factored form, more than two factors can be used. 9. A positive number can be indicated by placing a plus sign (+) before the number. 10. When the minus sign is placed between any two numbers, it indicates that the difference of the two numbers is to be found. 11. Division may be indicated also by writing the dividend above the divisor with a line between them.