Russian ⇄ Chinese English

не разбираться в элементарных вещах stresses
gen.	know as much about sth. as a pig about pineapples; not to know a B from a battledore; not to know a B from a broomstick; not to know a B from a buffalo; not to know a B from a bull's foot; not to know B from a buffalo; not to know beans; not to know chalk from cheese; not to know B from a bull's foot
idiom.	not to know B from a buffalo foot (Bobrovska); know as much about as a pig about pineapples (Yeldar Azanbayev)
Makarov.	not to know B from a battledore
Makarov., amer.	not to know B from a broomstick