IV. Use the correct form of the word given in each sentence. (1.pt) 17.He ____________ demonstrated his invention to the public. (succeed) 18.Charities rely on ____________ contribution. (volunteer) 19.Our teacher always ____________ us to work hard. (courage) 20.What is the correct ____________ of this word? (pronounce) 21.Her grades have ____________ greatly this semester (improvement) 22.It is always ____________ to write down important points. (wisdom)