阅读理解
Ever since humans have lived on the earth, they have made use of【B1】______forms of communication. Generally, this【B2】______of thoughts and feelings has been in the form of oral speech. When there is a language barrier, communication is【B3】______through sign language in which motions stand for letters, words and ideas. Tourists and the people【B4】______to hear or speak have to resort to this【B5】______of expression. Many of these symbols of whole words are very vivid and exact and can be used internationally: spelling, however, cannot. 【B6】______language transmits ideas or thoughts by certain actions,【B7】______intentionally or unintentionally. A nod signifies approval, while shaking the head indicates a【B8】______reaction. Other forms of non-linguistic language can be found in Braille (a system of raised dots read with the fingertips) , signal flags, Morse code, and smoke signals. Road maps and picture signs also【B9】______, warn and instruct people. While language is the most【B10】______form of communication, other systems and techniques also express human thoughts and feelings. A. unable D. guide G, form J. memorized M. accomplished B. negative E. expression H. positive K. Body N. Spoken C. mislead F. either I. difficult L. common O. various