RESEARCH DESIGN and METHODS This was a double-blind, randomized, crossover trial.

研究设计与方法本研究为一项双盲、随机、交叉试验。

youdao

RESEARCH DESIGN and METHODS This was a double-blind, randomized, crossover trial.

研究设计与方法本研究为一项双盲、随机、交叉试验。

youdao