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				           		它定义为受扰动统计量的期望值与实际值之差。
						        					            	 It is defined as the difference between the expectation of the perturbed statistic and its true value.
								    										 
								    				            	 youdao 
- 
				           		它定义为受扰动统计量的期望值与实际值之差。
						        					            	 It is defined as the difference between the expectation of the perturbed statistic and its true value.
								    										 
								    				            	 youdao