The price of live sardines with catfish effect is much higher than that of dead sardines, but the problem is that sardines are inactive and will die due to lack of oxygen during transportation. Therefore, Norwegian fishermen put a catfish in a fish tank full of sardines. If sardines want to escape the bad luck of being eaten, they must swim hard in the fish tank. The problem of lack of oxygen was solved, and sardines were successfully transported to their destination alive.
A story originated from hardships.
Wolves in Yellowstone National Park In the past 100 years, in order to protect endangered deer in Yellowstone National Park in Wyoming, all wolves were killed, and deer without natural enemies could live and reproduce comfortably. Many years later, the protected animals became a local disaster, and the overgrown population swallowed grass and leaves, causing great damage to forests and grasslands.
The long-term comfortable life has also made the deer gradually lose their natural running ability, and the population has encountered a new crisis. Since 1995, the US government has invested heavily in reintroducing wolves into Huangshi. In the face of natural enemies, the instinct of survival makes deer run again, rich food makes wolves grow rapidly, and the local ecology tends to be balanced and young.
Frustration can't stop the strong Zhang Haidi, who was severely paraplegic since childhood and was on the verge of death several times. He is very weak. However, in the past 20 years, she has studied four foreign languages, translated more than 1.6 thousand words of foreign language works, obtained a master's degree in philosophy, taught herself acupuncture techniques, and treated more than 1.0 million people, making great contributions. Compared with Zhang Haidi, what have we done as healthy people?