stay healthy preserve,stay,maintain,reserve这4个词均有保持 维持的意思preserve maintain,reserve都是及物动词.preserve=keep safe from decay ,risk.harm.danger,going bad etc.保存、保护 policemen preserve order in the streets maintain=keep up 保持 维持 维修 reserve=keep for a special purpose 保留 预定 I'LL reserve my opinion at his time
