[填空题]粉末涂料的种类主要有：（），（），（），聚氨酯粉末涂料等。

Passage Four
Sequoyah was a young Cherokee Indian, son of a white trader and an Indian Squaw (北美印第安女人). At an early age, he became fascinated by "tile talking leaf", an expression that he used to describe the white man’s written records. Although many believe this "talking leaf" to be a gift from tile Great Spirit, Sequoyah refused to accept that theory. Like other Indians of tile period, he was illiterate, but his determination to remedy tile situation led to the invention of a unique 86 character alphabet based on the sound pat- terns that he heard.
His family and friends thought him mad, but while recuperating (恢复) from a hunting accident, he diligently and independently set out to create a form of communication for his own people as well as for other Indians. In 1821, after twelve years of work, he had successfully developed a written language that would en- able thousands of Indians to read and write.
Sequoyah’s
A. Sequoyah developed a form of writing with the help of the Cherokee tribe.
B. Sequoyah was a very observant young man.
C. Sequoyah spent, twelve years developing his alphabet.
D. Sequoyah was honored by having some trees named after him.