For an answer, you would have to go back to the early 1920s.

2018年6月四级真题（第二套）听力 Section C

In the 1920s, Swiss psychologist Jean piaget proposed that children's cognitive abilities unfold naturally,like the blooming of a flower, almost independent of what else is happening in their lives.

2015年12月四级真题（第二套）阅读 Section A

Frederick's central idea, that "stove, sink and kitchen table must be placed in such a relation that useless steps are avoided entirely", inspired the first fully fitted kitchen,designed in the 1920s by Margarete Schütter-Libotsky.

2016年6月六级真题（第二套）阅读 Section C