SUN The Ozone Layer ATMOSPHERE What is the ozone layer? The ozone layer is like a blanket that surrounds the Earth. Ozone (O) is the main gas in this layer. 1) filters out the harmful rays of the sun allowing only the good rays, which give us light and heat, to reach the Earth. EARTH The problem 2) the 1980s, scientists discovered a large hole 3) the ozone layer over Antarctica. They found that some chemicals people used 4)... make aerosol sprays destroyed the ozone layer very quickly. The effects If the hole in the ozone layer continues to grow, our planet 5) be in danger. The temperature will rise and the sun's rays will become very harmful to our skin and eyes. Animals 6) plants will die and some species may even become extinct. The solution Although a 7) of countries stopped using some of these harmful chemicals in 1987, the ozone layer continues to be in danger. Scientists are trying there is still a lot of to find ways to help the ozone layer fix itself, 8) work to do.

1)down 2)make 3) will have 4)is leaving 5) won't drop 6) as soon as space probes, built, delivered, space journeys, space station, shuttle ТЕКСТ Nowadays travelling even to Earth’s closest neighbour planet Mars, let alone the planets in other /solar systems/, is still impractical. A trip to Mars and back would take more than a year. The /equipment/, supplies and fuel for such a trip would /require/ a vast rocket to launch a spacecraft from Earth. A return trip to the outer planets would take a lifetime. For the time being, /scientific research/ remain the best way of exploring distant worlds. Work is under way on a new international /shuttle/, which will be a base for a /space station/ . It is a modular structure, being built in space module-by-module, with sections being /delivered/ into orbit by the /space probes/ and unmanned launch vehicles. In the future, space stations such as this, or permanent bases on the Moon, could be a starting point for /space journeys/. Spacecraft would be /built/ and launched from there rather than from Earth. 

Б) notice - замечать, обращать (уделять) внимание;
    watch - наблюдать, следить, смотреть (что-то длительное, смотреть  телевизор, наблюдать как дети играют и т.д.)
    look - смотреть, взглянуть, посмотреть на что-либо, выглядеть;
    see - видеть, смотреть, представлять себе.
  
    Объяснение:
   - Look (at) — смотреть (на). На что-то неподвижное, статичное, неменяющееся (например, на картину, на небо, на снимок и пр.) Мы специально сосредоточиваем на этом внимание.
   - See - видеть. Мы видим часто предметы, которые попадают в поле нашего зрения, несмотря на то, заостряем мы на этом внимание или нет.
   - Watch - схоже с look, но watch — это смотреть на что-то меняющееся, наблюдать в течение некоторого времени за чем-то, что находится в действии и развитии.