Physical features at the site must be ascertained in order to make a sketch of the dam . 坝址处的自然条件必须查明,以便绘出坝的示意图。
Under natural conditions, the incubation period in feedlot cattle is uncertain in length . 在自然条件下,肥育舍饲牛的潜伏期,还没有确定。
These pigs had acquired lungworm infestations presumably containing masked influenza virus under natural conditions . 这些猪在自然条件下已受到含有隐蔽流感病毒的肺丝虫寄生。
Several species of mammals and birds are susceptible to the disease in nature or through experimental exposure . 几种哺乳动物和禽类在自然条件下或通过实验性裸露对此病是易感的。
Additional to these natural and structural advantages over the continental countries, there is the british flair for stock management . 除了在自然条件和结构方面超过大陆国家外,还有英国人民经营方面的天赋才能。