Second, three of the four goals Spain scored in the knockout stages came after they had made a substitution, and shifted their system slightly.
第二，西班牙淘汰赛阶段4个进球中的3个是通过调整后打进的。
2
Objective: To establish a highly efficient production system of chimeras by perfecting and normalizing the key steps of technology system of gene knockout mice.
目的：完善和规范基因剔除小鼠技术体系的关键技术环节，建立一套高效的嵌合体制备体系。
3
The technology system of gene knockout mice is a most urgently needed technique in the life science research, especially in human genomic project and medical animal models research.