[单项选择]

Kite flying is the sport of sending up kites into the air, by means of the wind, a light frame covered with paper, plastic or cloth. The frame can be one of many different shapes and is attached to a long string held in the hand or wound on a drum. Kites have a long history of practical application and many different types of kites have been developed to serve various purposes.
The ancient Chinese used bird-kites to carry ropes across rivers and valleys. The current folding kite which will dive excitingly is an improved type of such a kite. With its long flat body and single pair of bird-like wings, it looks just like a large bird in the air. The modern version is usually made of tissue-paper rather than the traditional silk.
Man-lifting kites were developed in ancient times, again by the Chinese, for getting information from walled cities and army camps. In fact, as recently as World War Ⅱ , German U-boats flew kites from their towers to lift people into the air
A. brown paper
B. plastic material
C. light-weight cloth
D. traditional silk