Упражнения и задания по грамматике

The future of our solar system

The Sun 1) (continue) will continue much as it is today until it 2) (enter) _______ its red giant phase in 4 to 5 billion years. Then, the core 3) (grow) _______ smaller and hotter until it finally 4) (finish) _______ burning the fuel in its nuclear core. When this 5) (occur) _______ the core 6) (become) _______ so dense that helium fusion will begin. When the helium atoms 7) (collide) _______, they 8) (form) _______ carbon (from 3 helium atoms) and oxygen (from 4 helium atoms). When this process 9) (begin) _______ the Sun 10) (produce) _______ enormous amounts of energy. The Sun 11) (grow) _______ larger as this energy 12) (increase) _______. It 13) (be) _______ over a hundred times its present size by the time it 14) (stop) _______ growing. This is why we use the term red giant. As the Sun 15) (expand) _______, it is probable that it 16) (absorb) _______ the Earth. When the Sun 17) (use) _______ up all its energy, it 18) (become) _______ a small white dwarf, and 19) (not make) _______ any more energy. After a few billion years, when it is completely cool, it 20) (be) _______ just a cold dark object.

7.7 Write these sentences, putting the verbs into the future simple or present simple:

1. I (give) it to them when they (visit) us. – I’ll give it to them when they visit us.

2. I (not send) the parcel until I (hear) from you. – I won't send the parcel until I hear from you.
3. As soon as they (phone) me, I (contact) you.
4. I (see) you before I (fly) to Paris.
5. They (send) you the money before they (leave).
6. When I (talk) to him, I (give) him your news.
7. She (visit) her parents before she (go) to the airport.
8. I (finish) this when I (be) at the office.
9. I (send) you a postcard when I (get) to Bermuda.
10. She (do) her homework before she (go) out.
11. After I (visit) the hospital, I (go) and see her parents.
12. I (phone) Mary when we (get) to San Francisco.
13. I (call) you as soon as we (sign) the contract.
14. He (not do) anything before you (tell) him to.
15. You (be) very surprised when you (meet) him.