The neutralization test is based on the neutralization of virus by specific antibodies found in the serum . 中和试验是基于病毒可被存在于血清中的特异性抗体。
Simplicity consists in a just medium, in which we are neither too much excited, nor too composed . 单纯存在于适度之中，我们在其中既不过分兴奋，也不过分平静。
It was soon recognized that the substances which provide this resistance could be found in blood serum . 人们不久就弄清了这种提供抵抗力的物质是存在于血清中的。
Hence lack of fusion and slag would exist at the weld root and create a large initial crack condition . 因而未熔透及夹渣存在于焊缝棍部，并造成大的初始裂纹条件。
In many plants, including most tree crops, nitrate nitrogen does not usually occur in the leaves . 在一些植物中，包括绝大多数的木本作物，硝态氮并非经常存在于叶片中。
The drying zone exists only in the lower layers of the grain mass and is truncated at its lower edge . 干燥区只存在于整仓谷堆的底层，并且干燥区底边的谷物总是不断地移走。
Oil is usually found in porous rock under a layer of impermeable rock which prevents it from escaping . 石油通常存在于多孔性的岩石中，上面覆盖着不可渗透的岩层，使石油不致散失。
Monterey pine needs mycorrhizae, which were already present or inadvertently introduced into many areas . 辐射松需有菌根共生，这种真菌可能存在于许多地方或已无意中被引入了许多地区。
It becomes more and more obvious that the reservoirs of infection reside completely, or almost completely, in the inflected pigs . 已愈明显的是，传染贮所完全或几乎完全存在于受传染猪内。
Many of the determinations used fall into the realm of microanalysis because of the small amounts of contaminants present in the samples . 因为存在于样品中的沾染物含量很少，所以许多测定方法属于微量分析范畴。
