C729 Cannot Answer

It was the first time that Sun Simian and Xu Jingchen had seen a microscope, so how could they use it? He touched left and right, not knowing where to look. In the end, he could only obediently wait for Li Xin to return.

Li Xin returned to the science department from the metallurgical base. He didn't even have time to drink a mouthful of tea before he was pulled to Xu Jingchen's laboratory