But the exact direction of causation is hard to establish.但是因果关系的具体程度是很难确定的.The gene is only part of the causation of illness.基因只是致病的部分原因。The causation of wheel breaking - up was analyzed through physical and chemical in...
“现在是可以对烟民自由开炮的时期。”我说道。"It's open season on smokers," I say.他们对英国船舶开炮.They let off their guns at the British ships.防空 部队开炮,击中了两架敌机.The anti - aircraft units opened fire and hit two of the enemy planes....