题目

________he is pleased with his success, Robert wonders what will happen to his private life.        A．As    B．If      C．When       D．Although 答案：D18．$\sqrt{3}$的相反数是（　　）A．$\sqrt{3}$B．$\frac{{\sqrt{3}}}{3}$C．-$\sqrt{3}$D．-$\frac{\sqrt{3}}{3}$