It mainly focuses on such research fields as fish culture in saline-alkali soil ponds in the Yellow River flood land, fish resources in the Yellow River, intensive aquaculture, and fish diets.
(It; mainly focuses; on such research fields as fish culture in saline-alkali soil ponds in the Yellow River flood land, fish resources in the Yellow River, intensive aquaculture, and fish diets)
It
mainly focuses
on such research fields as fish culture in saline-alkali soil ponds in the Yellow River flood land, fish resources in the Yellow River, intensive aquaculture, and fish diets