Challenging the Limits

Li Jinnian seemed much calmer in the face of Big Whale's excitement. Although his expression was still calm, one could tell that he wasn't as calm as his expression let off.

Oxygen deprivation causes headaches, fatigue, difficulty in walking, anxiety, shortness of breath, chest tightness, and pulmonary edema. In serious cases, one might even lose their life. Be it the highlands or the water, oxygen deprivation is a problem that humans have never been able to overcome.

Furthermore, frogmen mostly carried out underwater missions. The oxygen resistance test played an important role in the soldiers' selection. It could even decide whether some would go or stay.

Li Jinnian stared at the rising numbers and glanced at the time calmly. A dim light gathered in his cold eyes and turned into a ray of light as bright as the winter night.