這些因素，加上越來越多的教育研究，共同表明在需要的時候學習是最有效的。

這些因素，加上越來越多的教育研究，共同表明在需要的時候學習是最有效的。

Results (English) 1:

These factors, combined with a growing body of educational research, suggest that learning is most effective when it is needed.

Results (English) 2:

These factors, together with a growing number of educational studies, have shown that learning is most effective when needed.

Results (English) 3:

These factors, combined with a growing body of educational research, suggest that learning is most effective when needed.