在接下来的一年里我不得不上额外的几门课程，我选择在接下来的暑假修完近世代数和微分方程。
I had to take a few extra courses during the next year, and I chose reading courses in modern algebra and differential equations for the summer afterwards.
西方程序的下载更具有选择性。
The downloading of Western applications was now more selective.
权重选择和使用复杂的回归方程应合理。
Selection of weighting and use of a complex regression equation should be justified.
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