Word

HSK	Not in HSK
FREQUENCY	Unknown

化学需氧量 huà xué xū yǎng liàng

DEFINITIONS

chemical oxygen demand (an environmental indicator)

CHARACTERS

化 huà HSK 3	change, convert, reform; -ize
学 xué HSK 1	learning, knowledge; school
需 xū HSK 3	need, require, must
氧 yǎng HSK 6	oxygen
量 liàng HSK 4	measure, quantity, capacity