WHY SHOULD WE BRUSH OUR TEETH?

NAME : NURHASAN (08211210078)
CLASS : 3A-2

WHY SHOULD WE BRUSH OUR TEETH?
We brush our teeth because we know that if we do not bits of food will collect in the gaps between our teeth. The food will go bad and start to smell. Our teeth will start to darken in color, and eventually they will also go bad. At some point, we will have no teeth left. This process can be explained biologically as follows. Our teeth naturally become coated with a substance called plaque, which contains bacteria. When these bacteria come into contact with sugars, they convert the sugar into acids such as lactic acid. The acids attack the enamel of your teeth and make holes in it. Bacteria enter through these holes and attack the soft insides of your teeth. Very soon you have no teeth left. To stop your teeth from decaying, you have to remove the plaque as often as possible. This means cleaning your teeth every night and every morning. Many people clean their teeth with toothbrush and toothpaste. Toothpaste contains a polishing agent such as chalk and a small amount of a cleaning agent such as sodium lauryl sulphate. These are usually blended with a flavouring, such as peppermint, and a sweetener. In addition, a preservative is added to stop the toothpaste from going bad. It is also necessary to add another ingredient to keep the toothpaste from drying out. So toothpaste is a mixture of chalk and soap. Dental scientists claim that a small amount of fluoride can reduce the chance of decay. Fluoride strengthens the enamel and helps it to fight off the acid attack.

BEES

NAME : NURHASAN (08211210078)
CLASS : 3A-2
BEES
Bees are useful insect. There are about 20,000 kinds of bees, but only honey bees make honey. Honeybees live in groups called colonies. Each colony has one female queen bee, tens of thousands of workers bees, and a few hundred males, or drones. Honeybees live in hives. Inside their hive, the bees make a honeycomb of wax. The honey-comb is a kind of bee apartment building, full of six-sided rooms in which the bees raise young and store food. The queen bee lays thousand of eggs. Worm like larva hatch from the eggs, each larva becomes a pupa, which looks partly like a larva and partly like an adult bee. The pupa then becomes an adult bee. Worker bees feed the young, clean and guard the hive, and fly to and from flowers. They collect tiny grains of pollen and a sweet liquid called nectar for food. The pollen is food for young bees. Worker bees use the nectar to make honey. Without bees bringing pollen from flower to flower, many plants could not make seeds. Queen bees and worker bees have stings. Workers use their stings to defend themselves and their hive. A queen uses their stings to kill other queens. Most other kinds of bees live alone instead of in a colony. These bees make tunnels in wood or in the ground. The queen makes her own nest. People admire bees for their busy ways. People called beekeepers keep bees for honey and for the beeswax the bees use to build their honeycombs.