So, basically, withholding information is not the same thing as lying, but depending on the situation, you will have to decide whether it is better to withhold the information or not.
HCH may refer to: Hampton Court House, an independent school in Surrey, UK. Hexachlorocyclohexane, a group of chemical compounds. Holmes Chapel railway station (National Rail station code), in Cheshire, England.
NADH, short for nicotinamide adenine dinucleotide, is an important pyridine nucleotide that functions as an oxidative cofactor in eukaryotic cells. NADH plays a key role in the production of energy through redox reactions.