题目投掷项目有效的试掷成绩应被测量,失败应以( )标记。A. "×"B. "-"C. "r"D. "0"投掷项目有效的试掷成绩应被测量,失败应以( )标记。A. "×"B. "-"C. "r"D. "0"题目解答答案A. "×"