进出口货物报关单“数量及单位”栏必须按海关法定计量单位和成交计量单位填报。成交计量单位与法定计量单位不一致的，须填报与海关法定计量转换后的单位及数量，同时还需填报成交计量单位及数量。( )

He thoroughly understood the society（）

A.he had grown up

B.which had he grown up

C.in which he had grown up

D.he had grown up in it