Plans grow(46)in almost every part of the world. We see(47)such plants as flowers, glass, and tree nearly every day. Plants grow high on moutaintops, far in the oceans, and in many deserts and(48)polar regions
Without plants, there could be not life on earth. Man could not live without air of food and so he could not live without plants. The oxygen in the air we breathe comes from plants. The food we eat also comes from plants or from animals that eat plants. We build houses and make many(49)useful products from lumber cut from trees. (50) Much of our clothing is made from the fitbers of the cotton plants.
Scientists belive there are more than 350,000 species of plants, but no one knowns for(51)sure. Some of the smallest plants, called diatoms, can be seen only with a(52)microscope . A drop of the water may hould as many as 500 diatoms. The largest living things are the giant sequoia trees of California. Some of them stand more than 290 feet high and measure over 30 feet wide
Scientist(53)divide all living things into two main groups - plants and animals. It is usually easy to tell the two(54)apart . Almost all kinds of plants stay in one place, but nearly all species of animals move about under their own power. Most plants make their own food from air, sunglight, and water. Animals cannot make their own food. The basic units of all life, called cells, are also different in plants and animals. Most plants have thick wall that(55) contain a material called cellulost. Animal cells dl not have this material.