Man is different from an animal only in certain respects. His bodily organs do not differ vastly from those of other mammals such as sheep, cow, a horse or a dog. Yet he is the only animal to invent tools and make use of them. It is so, because he is mentally different. Thus, over the years, he has ...

• Word Count: 633
• Approx Pages: 3
• Grade Level: High School

HISTORY OF AVIATION: The first form of an aircraft was the kite, designed in the 5th century. In the 16th century, Leonardo da Vinci studied bird's flight, and later produced the airscrew and the parachute. The airscrew, leading to the propeller later on, and the parachute were tremendously impor...

• Word Count: 2065
• Approx Pages: 8
• Grade Level: High School