natural color 自然色；天然色；本色natural coke 天然焦炭natural circulation waste-heat boiler [經(jīng)濟(jì)學(xué)]自然循環(huán)廢熱鍋爐natural circulation evaporator 自然循環(huán)蒸發(fā)器natural circulation 自然循環(huán)natural childbirth n. 自然分娩；不用藥物的分娩natural centrism [哲學(xué)]自然中心主義natural calamity [環(huán)境][農(nóng)] 自然災(zāi)害；天災(zāi)natural building sand [土木建筑工程]天然建筑砂natural building natural brown kraft wrapping paper [經(jīng)濟(jì)學(xué)]本色牛皮包裝紙natural bristle 天然鬃毛natural bridge state park natural breadth [物理學(xué)]自然寬度natural boundary condition [數(shù)] 自然邊界條件natural boundary [數(shù)] 自然邊界natural blood relation [法學(xué)]自然血親natural bitumen 天然瀝青natural biotic community [能源科學(xué)技術(shù)]自然生物群落natural bile acid resources [地球科學(xué)]天然膽酸類資源