source

• An external force is one whose source is outside the system .
  外力是来源于系统之外的力。
• Fish oil is a particularly potent source for vitamin a .
  鱼肝油是维生素A特别有效的来源。
• Peasants therefore have no source of external income .
  结果农民丧失了任何其它的收入来源。
• The interior life was a source of identity and of power .
  内在的生命力是个性和力量的源泉。
• It has its source in envy .
  它的根源在于嫉妒。
• Blackberries are a fairly good source of iron and vitamin c .
  黑莓果含有丰富的铁和维生素C。
• These rays originate at different points of the source .
  这些光线是以光源上的不同点发出的。
• The sun seems to be the most promising source for the future .
  太阳似乎是未来有希望的能源。
• Automobile exhaust gases are considered the major source .
  据认为汽车排出的废气是主要来源。
• The most widely used large energy source is the air gun .
  应用最为广泛的大的能量源是空气枪。