like: hiệu lực
Intermediate Level Advanced Level
Composite Words Listening Comprehension Oxford Topics Duolingo Topics 315 Activities
BEGINNER LEVEL
exact:
VNEN 
hiệu lực * ☊ 
validity, effectiveness * ☊
[ hiệu ] : store, shop; sign, signal, mark, brand, trademark
[ lực ] : force, energy, strength, ability