When an organism is completely encapsulated and preserved, it becomes a fossil, therefore turning into evidence of things that once lived.

A．thereby

B．as a result of

C．so

D．in the end

在西欧中世纪，骑士教育是（）的教育。

A.世俗封建主

B.教会封建主

C.资产阶级

D.城市平民