为进一步探寻引起学习效率下降的原因,我们对实验组和参照组进行了对比研究。()
A. In order to investigate the reason for the decrease of learning efficiency, a comparative study was conducted between the experimental group and the control group.
B.In order to look into the reason for the decrease of learning efficiency, we conducted a comparative study between the experimental group and the control group.