"So you said that you wanted to experiment with Tibet, although I agreed, but I didn't have much hope for this matter." Comrade Li Er also said truthfully.

"Your Majesty, you have to have faith." Zhang Nan was also very helpless when he saw Comrade Li Er's depressed appearance, this has not yet started, and he first felt that this thing could not be successful, how could this be done?

"It's not that I don't want to have confidence, it's just that you don't even know about this strange disease in Tibet, so what should we do if our people can't go up to the plateau at all?" Comrade Li Er said with a bitter face.

"Your Majesty, let's talk about this strange disease in Tibet, the minister has not heard of any strange disease on that plateau until now."

"It's not so much a strange disease, it's more a curse, a curse that our Tang Dynasty can't use force against Tubo." Li Erdao.

"That's pure." Zhang Nan said silently in his heart.

In fact, during the reign of Songtsen Gampo, the relationship between Datang and Tubo was not so bad, on the contrary, compared with other neighbors of Datang, Tubo was very well-behaved.

Historically, Songtsen Gampo sent envoys to reconcile with the Tang Dynasty in the eighth year of Zhenguan, and the Tang Dynasty also sent ministers to Tibet. In the tenth year of Zhenguan, Songtsen Gampo sent a special envoy to Chang'an to ask for marriage, Li Er did not agree, Songtsen Gampo then used the Tang Dynasty's vassal state Tuyuhun to make a hindrance, led 200,000 troops to invade Tuyuhun, and the Tang Dynasty sent 50,000 troops, commanded by Hou Junji and Niu Jinda, to repel the attack of Tubo. Later, Li Er decided to appease the Tibetans and married a distant niece, Princess Wencheng, to Songtsen Gampo.

This is also the famous Princess Wencheng into Tibet.

When Li Zhi succeeded to the throne, Tubo was even more well-behaved, and Li Zhi canonized Songtsen Gampo as the king of Xihai County and the commander of the horses.

In order to show his loyalty, Songtsen Gampo once sent a letter to the secretary Sun Wuji and other ministers: "At the beginning of the Son of Heaven's accession to the throne, if the subordinates have disloyalty, they should be sent to the country to eliminate them." ”

This image of a good son is deeply liked by Datang.

Although there were many forks in the middle, the Tang Dynasty still destroyed Tubo in the late Tang Dynasty, when the national strength was the weakest.

Therefore, Comrade Li Er now said that Tubo has a curse on the Tang Dynasty, and Zhang Nan naturally cannot believe it.

"Whenever our people want to spy on intelligence, they always feel stuffy in their chests and can't breathe, and even the doctor can't see the reason, so they can only carry it, but there are very few who can survive." Li Er sighed and said.

Zhang Nan listened to it for a long time, and finally knew what Comrade Li Er was talking about, isn't this altitude sickness? Curse, curse a ghost.

Those who spy on intelligence must be nervous or excited, or they have to run two steps if they are discovered, and they are not adapted to the climate of the plateau, so something will definitely happen.

And he couldn't get timely treatment, and he had altitude sickness and continued to stay on the plateau, isn't that waiting for death?

According to physiological and hygiene experimental research, the most suitable altitude for human survival is 500 meters ~ 2000 meters. The altitude of 1500 meters is the low altitude, the middle altitude is 2500 meters, and the high altitude is more than 3500 meters.

As the largest plateau in China and the highest in the world, the Qinghai-Tibet Plateau, as well as the "Roof of the World" and the "Third Pole", is generally between 3,000 and 5,000 meters above sea level, with an average altitude of more than 4,000 meters.

This pair of Tang people, who are used to staying in the plains on weekdays, naturally can't stand it. And Datang doesn't have so much common sense, whenever he encounters something, he pushes it on the ghosts, ghosts, gods and gods, doesn't this increase his psychological burden?

"Your Majesty, the minister should know what this thing you are talking about?" Zhang Nan said with a smile.

"Oh? Qingquan, do you know the curse of Tibet? Li Er asked with some curiosity.

"Hey, what's the curse here, this is a disease, and it's a disease that can be easily cured, the emperor doesn't have to worry so much." Zhang Nan said with relief. It looks like it's not a problem.

"Sick? So why can't the doctor who followed him see what the disease was? And the patients can't get better at all after taking the decoction," Li Er's face was strange.

"Decoction? You don't take decoction for this disease, as long as you send people down to the plateau, this disease will be cured. Zhang Nan said.

"It's as simple as that?" Li Er asked with some disbelieving.

"It's that simple." Zhang Nan said.

"Okay, since you said it's a disease, then you can tell me what kind of illness it is." Li Er commanded.

When Zhang Nan heard Li Er say this, he immediately knew that his opportunity to pretend to be a calf had come again. Zhang Nan will not let go of every opportunity to suppress Comrade Li Er's IQ.

"Your Majesty, the minister calls this disease altitude sickness."

"Altitude sickness?"

"That's right, people who suffer from this disease, headache, insomnia, loss of appetite, tiredness, difficulty breathing and other symptoms, some people can be relieved in a few days, but some people who are not in good health can not pass this hurdle, so if this situation occurs, and it does not get better, you should return immediately and do not waste there." Zhang Nan said.

"Then why do you have altitude sickness?" Li Er is a curious baby at this time, and his desire for knowledge is very strong.

"Your Majesty, do you remember what the minister said about oxygen?" Zhang Nan said.

"Then I must remember that when Guanyin was sick, she relied on oxygen to save her life." Li Erdao.

"That's the reason, the higher the altitude, the lower the oxygen content will be, Your Majesty, do you think that a normal person eats five bowls of rice on weekdays, and now he only eats one bowl, so can this person's body feel better?" Zhang Nan thought about it, and then gave Comrade Li Er an easy-to-understand explanation.

"Is it that simple? Why don't I think so? Besides, who would eat five bowls of rice? "Comrade Li Er's bar essence attribute can be said to be full, especially in front of Zhang Nan, Comrade Li Er can be said to be the king of bar essence, if he doesn't lift the bar twice with Zhang Nan, Comrade Li Er is "I feel uncomfortable".

"The activity of all tissues and cells in the body depends on oxygen, and an important way to supplement oxygen is blood circulation. When oxygen from the air enters the alveoli, there is more oxygen in the alveoli than in the blood, so the oxygen enters the blood from the alveoli and binds to the hemoglobin in the red blood cells to transport it throughout the body. There is more carbon dioxide in the blood than in the alveoli, so carbon dioxide enters the alveoli from the blood and is excreted outside the body through exhalation. ”

"People who live in plain areas for a long time can generally only adapt to a reduction of 20% of the partial pressure of oxygen, and more than this value can cause significant discomfort. Therefore, people who live with high air pressure and high oxygen content all year round tend to be dizzy and weak when they are in high altitudes, which is a manifestation of low oxygen use in the body. ”

As soon as he spoke, Comrade Li Er's jaw was about to fall.