Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks

Ever since humans (26) _____ the earth, they have made use of various forms of communication Generally, this expression of thoughts and feelings has been in the form of oral speech. When there is a language barrier, communication is accomplished through sign language in (27) _____ motions stand for letters, words, and ideas. Tourists, the deaf, and the mute have had to resort to this form of expression. (28) _____ of these symbols of whole words are very picturesque and exact and can be used internationally, spelling, however, cannot.
Body language (29) _____ ideas or thoughts by certain actions, either intentionally or unintentionally. A wink can be a way of flirting or indicating that the party is only joking. A nod signifies approval, while sharking the head indicates a negative reaction. Other forms of nonlinguistic language can be found in Braille, signal flags, Morse code, and smoke signals. (30) _____ verbalization is the most common form of language, other systems and techniques also express human thoughts and feelings.