目的：探讨氧化亚氮（N_2O）吸入麻醉下行无痛人工流产的有效性与安全性。

Objective: To investigate the analgesic effect and the safety of N2O inhaled in induced abortion.

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选用南方牧场土壤，在盆栽条件下，研究了氮锌交互作用对土壤中锌形态和生物有效性的影响。

Effects of interaction between nitrogen and zinc on forms of zinc in yellow- brown soil collected from a pasture in southern China were studied under pot- culture conditions.

youdao

选用南方牧场土壤，在盆栽条件下，研究了氮锌交互作用对土壤中锌形态和生物有效性的影响。

Effects of interaction between nitrogen and zinc on forms of zinc in yellow- brown soil collected from a pasture in southern China were studied under pot- culture conditions.

youdao