1. He (keep) looking at her, wondering where he (see) her before. 2. He (help) me as soon as he (give) us the answer after she (finish) his work. (speak) to 3. She her husband. 4. When we (arrive) at the station I (try) to find a porter. 5. Stan (say) good-bye to Dick as soon as he (get) the money. (let) them in after they (knock) the door 6. Joe three times. (make) them 7. They some sandwiches. 8. Joe (leave) for school before I (be) the gardener at the Lees' before Dick (come). 9. John (not worry) as everything (be) all right so far. 10. I 11. When Mark (have) no idea what (happen). (turn) to say good-bye to them, they (already go). 12. They (be) tired and sleepy because they (travel) all through the night. (come)​

1)To control an economy is the same as to intervene in it.
2) TO analyze the labour market, an economist should first explain how people allocate their time to production. 
3)It can be Home Trade when it deals with the customers of a native country and Foreign Trade that is trade between nationS in the form of export and import transactions and capital movements.
4) Each faculty IS headed by a dean and has two forms of academic training : full-day and correspondence.
5)The market mechanism involveS an interaction of priCe, quantity, supply, and demand of resources and products.
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The atmosphere pollution is most serious environmental problem because of the greenhouse effect. it means that the climate becomes warmer and warmer every day. This is dangerous because it causes the melting of Artic ice and the level of the Ocean can become higher. So, water will cover some land.Another great problem is water pollution. Factories and plants produce the water polluted by poisons or oils and let out this water into rivers and the seas. That is dangerous for the wildlife and for people.
They also produce gases and substances which destroy the ozone layer of the atmosphere.It is dangerous because this ozone layer protects the Earth from the space radiation. We can help keep this ozone layer, if we use ozone-friendly substances and sprays.

Загрязнение атмосферы является наиболее серьезной экологической проблемой из-за парникового эффекта. это означает, что климат становится теплее и теплее с каждым днем. Это опасно, потому что оно вызывает таяние арктических льдов и уровень океана может стать выше. Так, вода покроет землю.Другой большой проблемой является загрязнение воды. Фабрики и заводы выпускают воду, загрязненную ядами или маслами и выпускают эту воду в реки и моря. Это опасно для дикой природы и для людей.
Они также производят газы и вещества, разрушающие озоновый слой атмосферы.Это опасно, потому что этот озоновый слой защищает Землю от космической радиации. Мы можем сохранить озоновый слой, если мы будем использовать озонобезопасные вещества и спреи.