Empirical study on the standardization of sentencing of drug crimes in northwest China 并列题名：Empirical study on the standardization of sentencing of drug crimes in northwest China Empirical study on the man-land relationship in Northwest China Empirical study on the operation mechanism of criminal procedure in China Research on the standardization of community corrections in China a study on the present situation of stage manager in Southwest China Study on the standardization pig-breeding development of China 并列题名：Empirical study on the man-land relationship in Northwest China