2017-11-01
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Use the text 1 and figures (2.1; 2.2; 2.3; 2.4):
2.7 Match the terms with their definitions:
| Needle | Small, flat, green part of a plant |
| Flower | Smaller, “mini-leaf”. Some leaves are made up of several leaflets |
| Leaf | The leaf of a pine tree. Pine leaves are long and skinny, not flat and rounded like most leaves |
| Bud | The process where a plant creates oxygen from carbon dioxide. It is very important, since plants make oxygen for animals (including people) to breathe |
| Leaflet | The part of a plant that helps it grow new plants. The flowers have nectar and pollen in them |
| Photosynthesis | A small bumpy part of a twig or stem on a plant. This is where new leaves or flowers are made in spring |
Skim the text 2. Single out the key sentences and write down them.
Text 2
Tree shapes
There are many reasons why tree shapes differ. A tree growing in poor soil may be stunted due to lack of nutrients, and a tree growing right next to an apartment building may have more leaves on the side facing the sun. Different kinds of trees have their own unique form, but the form that any tree has is also affected by the environment where it grows. Sunshine and water are both essential for a tree to survive, and both influence tree height, crown shape (for example, a round treetop or the cone shape of a pine tree), and the form of leaves.
In general, the crowns of trees take on two basic forms:
Conical – In conical forms – such as the familiar spruce tree – the terminal bud grows much faster than the lateral branches. The resulting conical form helps the tree shed snow and its compact shape resists wind pressure, so the conical form is most common in trees growing farther north. The conical-shaped needleleaf trees are well adapted to the cold and arid conditions of the taiga. The thin triangular shape of the trees means that the snow falls straight off without weighing down and breaking the branches. The narrowness of the leaves reduces the surface area through which water can be lost in times of drought. A waxy coating also prevents water loss.
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Round – In the milder climatic areas associated with southern parkland, the predominant form is that of the spreading, more rounded crown, typical of aspens and elms.
