Real mastery of a word must be demonstrated through being able to (1.) it and (2.) it with understanding. 1.) a.} hear b.} explain 2.) a.} speak b.} translate

1.explain 2.speak.It says real mastery of word.So we should pick up explan in the fist one cause 'hear' is so superficial and the second answer should be 'speak' cause it says with understanding, which means everybody should figure out what we wanna say.