ere were many problems during the research and development process. Several experts researched until dawn, while Ou Yan went home very late to avoid worrying her parents, and rushed to the laboratory...whether he liked it or not, she just walked past them.The four security guards at the main gate recognized Li Yuanfu and Song Qiao Ying, and hurriedly bowed to welcome them, "Mr. Li, Mrs. Li, you've a...