Section 3. Task 1. Learning to rephrase.

1.The Landsats are two butterfly-shaped spacecraft that were sent into orbit around the earth in 1972 and 1975.

2.They circle the earth 14 times every 24 hours at a height of 570 miles, or 918 kilometers, above the earth.

3.From the photographs sent from the satelites, scientists are learning things about the earth they have never known before.

4.In false colours, water is black, cities are blue-green, rock is brown, healthy plants are red and diseased plants are green.

The white areas show barren land.

5.Because photographs from the satelite are taken looking directly down on the land from such a height, they are more accurate than earlier photographs taken from airplanes.

6.The second use of these Landsat photographs is to help find oil and minerals.

7.Although these two Landsats have already produced a lot of very important information about the world, they are just the beginning.

8.Later Landsats may be equipped to photograph even smaller areas or they maybe equipped with radar.