Answer:
1. Known to sailors round the sector because the doldrums, the Inter-Tropical Convergence Zone, (ITCZ, reported and on occasion called the “itch”), is a belt across the Earth extending about five degrees north and south of the equator.
2. Polymer optical fibres are usually made from a polymethyl methacrylate (PMMA, acrylic) core, surrounded by a cladding made from fluorinated polymer. The cladding material must be of lower refractive index than the core in other words, light must travel slower through the core material than the cladding.
3. A greenhouse is a building with glass walls and a glass roof. Greenhouses are used to grow plants, such as tomatoes and tropical flowers. A greenhouse stays warm inside, even during the winter. In the daytime, sunlight shines into the greenhouse and warms the plants and air inside.
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