In that school, English is compulsory for all students, but French and Russian are       .

A．special

B．regional

C．optional

D．original[

我国远洋渔业企业在公海或按照有关协议规定，在国外海域捕获并运回国内销售的自捕水产品(及其加工制品)，视同国内产品，不征收进口关税和进口环节增值税。