A．hedges are considered as a strategy of being more precise in reporting results
B．authors try to appear humble rather than arrogant or all-knowing
C．hedges are used as a strategy to present unproven claims with certainty
D．authors tone down their statements in order to reduce the risk of opposition

A．房产销售收入
B．将房产提供给债权人使用而放弃的租金收入
C．彩票中奖收入
D．出版书籍取得的收入