5. what are they doing now? (present progressive) they are working in the reading room.(present progressive) they have been working there for three hours already. (present perfect progressive)
9. have you found your notebook? (present perfect) no! I'm still looking for it. (present progressive) I have been looking for it for two hours(present progressive), but haven't found it yet.(present perfect)
10. you have been playing with a ball for three hours already. (present perfect progressive) go home and do your homework
15. what are you doing?(present progressive) I'm reading. (present progressive)I have been reading for two hours already.(present perfect progressive) I have already read sixty pages. (present perfect)
20. come along, Henry, what are you doing now? (present progressive) I'm waiting for you for a long time (present progressive)
6 3 При необходимости напишите предложения с вс форм.
1 Сходить / на выпускной / баночка / стоит / много денег Посещение выпускного вечера может стоить больших денег.
2 Вы / не можете / организовать / большую вечеринку / без / иметь / несколько проблем 3 Моя мама / действительно / наслаждайтесь / идите / на свадьбу
4 Носите / специальную / не уметь / хорошо / петь / или / танцевать
7 Некоторые люди / терпеть не могут / находиться / в большой толпе / на концерте 8 Самое лучшее / о / пойти / на фестиваль / быть / увидеть / фейерверк
IV.
1. The word "mathematics" comes from Greek language.
2. By origin or etymologically, "mathematics" means "something that must be learnt or understood", perhaps "acquired knowledge" or "knowledge acquirable by learning" or "general knowledge".
3. Mathematics as a science, viewed as a whole, is a collection of branches.
4. The largest branch is that which builds on the ordinary whole numbers, fractions, and irritional numbers - simply, the real number system.
5. The whole numbers or integers.
6. Theorems.
V. c