BIRDS MAKE UP THE CLASS AVES.There are more than 9,000 species , almost all of which can fly.(the only flightless birds are Penguins , ostriches, rheas,cassowaries, and kiwis ). The ability to fly is reflected in the typical bird features ; forelimbs modified as wings , a streamlined body ; and hallow bones to reduce weight. ALL birds lay hard-shell eggs , which the parents incubate.Birds beak and feet vary according to diet and way of life .Beak range from general purpose types suitable for a mixed diet .Feet range from the webbed "paddles" of ducks to the talons of bird of prey. Plumage also varies widely , and in many species the male is brightly colored for courtship display where as the female is drab.
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SCIENTISTS have developed a tiny implant , no bigger than a pinhead , which sits inside&n bsp; the cor nea to reverse vision problems in aging eyes . With the age ,some people's ability to switch focus between near and distant objects diminishes , a condition known as presbyopia .It can skew the perception of depth and makes reading in poor light impossible . The new implant slightly increase the curvature of the cornea,which allows the eyes to focus again.This new technique ,known as a' Raindrop corneal inlay' was developed by scientists at Revision Optics in California.The first operations have now been carried out at a clinic in Warwickshire .The inlay is called Raindrop because it is in the shape of a droplet and is made of hydro-gel, a substance which is also used in contract lenses. Hydro gel is 80 percent w
THERE ARE MANY KINDS OF DESERTS IN THE WORLD-Such as snow deserts, water deserts and sandy or dry deserts.In Sandy or dry desert there are vast tracts of sand with very high temperature and difference between day and night temperature..There are sand storms that blows hard and make life dangerous.Sand dunes are ever changing their shapes and places by the work of winds. Animals and plants adapt themselves to be able to survive in this harsh environment.Some animals like antelopes have developed tricks so that they are able to withstand thirst. " PLANTS CACTUS - CACTI OR CACTUS have an outer waxy layer and their leaves have evolved into thorns to prevent evaporation of water.In the morning their thorns and outer waxy layer able to absorb dew drops .They store water water in their bodies and roots a