More than ten days later, Tubo Dalun Lu Dongzan entered Chang'an City, the capital of the Tang Dynasty, and officially asked the Tang Dynasty to marry the princess on behalf of Tubo Zanpu Songzan Gampo.

Hanyuan Palace, in the early dynasty, the Tang Emperor Li Shimin summoned the Tubo Great Lunlu Dongzan.

Li Shimin said to Lu Dongzan: "Since I allowed my Tang princess to marry, all the countries that my Tang princess married are not barren countries that only show off their strength, but countries with developed politics, economy, military and culture. Your Tubo force, I have been taught by the Tang Dynasty, it is true that the soldiers are brave and tenacious, but I don't know how your Tubo politics, economy, and culture are? In a big way, you are the right-hand man of Tubo Zanpu Songtsen Gampo, and this resourcefulness must be outstanding in your Tubo. Today, I will test you, if you can deal with the three problems I have given you, I will marry me as a princess of the Tang Dynasty and marry you to Tubo. What do you think? ”

Lu Dongzan's brows furrowed slightly, but he had to bow respectfully and salute: "Please ask Tian Khan to ask the question." ”

Li Shimin smiled slightly, clapped his hands, and soon a eunuch brought a tray.

In the tray is a fist-sized nine-song pearl, the pearl is bright and shining, and next to the pearl is a red silk thread.

Li Shimin said to Lu Dongzan: "My first question is to ask Da Lun to thread this nine-song pearl with silk thread. ”

Lu Dongzan picked up the Jiuqu Pearl with his left hand, and after a closer look, he found that on the Jiuqu Pearl, there was a small hole like a grain of rice, which ran through the left and right. Lu Dongzan picked up the silk thread with his right hand and pointed it at the small hole, and after several attempts, it ended in failure.

Li Shimin and the Tang Dynasty ministers looked at each other and smiled.

Lu Dongzan did not panic, but asked the eunuch to find an ant and a jar of honey with unusual calmness.

With Li Shimin's consent, the eunuch brought the ants and honey that Lu Dongzan wanted.

Under the gaze of Emperor Li Shimin of the Tang Dynasty and the ministers of the Tang Dynasty. Lu Dongzan tied the silk thread around the ant's waist, and then placed the ant's head on the small hole of the Jiuqu Pearl, and at the other end of the small hole, Lu Dongzan coated it with honey. The sweetness of the honey made the ants quickly drill into the hole, quickly climbed to the other end of the hole, and began to lick the honey, while Lu Dongzan took the opportunity to untie the silk thread on the ant's waist, connected the silk thread end to end, and strung the pearl of Jiuqu.

The Tang Dynasty ministers suddenly exclaimed: "What a way! This Tibetan theory is really a smart person. ”

The Tang Emperor Li Shimin was slightly displeased. Said a little helplessly: "This question, I count you to pass the test." ”

Li Shimin clapped his hands again, and two guards carried a log and entered the main hall.

The log is about ten meters long, and the end is generally thick.

Li Shimin said to Lu Dongzan: "Please talk about it, distinguish the roots and tips of this log, this is my third question." ”

As soon as the words fell, Lu Dongzan frowned, and the Tang Dynasty ministers also discussed:

"This. The head and tail are generally thick. How can you tell the difference between the roots and the tops? ”

"Yes, Your Majesty's question is too tricky. Except for the person who cut and processed this log, who will know the roots and tops of this log? ”

"I look at this Tibetan treatise - Lu Dongzan is in trouble. It's just too hard. ”

After some contemplation, Lu Dongzan said to the Tang Emperor Li Shimin: "Please move, Your Majesty, here the minister can't judge which side of this log is the root." Which side is the treetop, but as long as you go to the lake, you will be able to judge the roots of this log. The treetops come. ”

Emperor Li Shimin of the Tang Dynasty looked at Lu Dongzan with a smile on his face and said, "Okay, I will allow you to invite you to move to the Xuanwu Lake in front of the Hanyuan Palace." If you still can't judge the roots and tops of this log, or if you are wrong, I will punish you severely for your deceit. ”

As he spoke, the Tang Emperor Li Shimin stood up and walked towards the Xuanwu Lake outside the Hanyuan Palace, and the courtiers also followed closely behind Li Shimin.

Next to Xuanwu Lake, Lu Dongzan asked the eunuch to throw the log into the water, and suddenly there was such a scene, one end of the log gradually began to sink, while the other end gradually warped.

Lu Dongzan pointed to the log and said to the Tang Emperor Li Shimin: "Qiqi Heavenly Khan, the sinking end of this log is the root of the tree, and the upturned end is the treetop. ”

Li Shimin was noncommittal, but asked people to go and inspect it.

After inspecting the marks on the log, the inspector nodded heavily to the Tang Emperor Li Shimin.

Li Shimin's face suddenly turned gloomy, and he said coldly to Lu Dongzan: "Tell me why you made such a judgment?" ”

Lu Dongzan opened his mouth and said: "Your Majesty, the minister just thinks that the roots of this tree grow longer, and it will naturally be heavier, and the treetops of this tree will grow shorter than the roots, and in the case of the same thickness, it will naturally be lighter, so even if we see that they are the same thickness, in fact, their own weight is not the same." On the water, the roots of the log are heavier and will naturally sink, and the treetop part of the log will be lighter, so it will naturally warp. ”

Li Shimin looked at Li Xuan with a puzzled face, hoping that Li Xuan could help him judge whether what Lu Dongzan said was right.

Li Xuan nodded at Li Shimin. Li Xuan knew in his heart: What Lu Dongzan said was right, but it was also wrong. This involves the physical density of later generations, the density of tree roots is large, the density of tree tops is small, and under the same volume, tree roots are indeed heavier than tree tops. However, if Li Xuan talks about density with Emperor Li Shimin of the Tang Dynasty and the ministers of the Tang Dynasty, I am afraid that few people can really understand it.

Li Shimin said helplessly to Lu Dongzan: "What you said is good, this question is also considered to have passed the test." “

With that, Li Shimin once again led his ministers to move to the Imperial Horse Prison.

In the stable (jiu), the horses are in groups, and the horses gather together in twos and threes, grazing leisurely.

Li Shimin pointed to the stable and said to Lu Dongzan: "In this stable, there are five hundred mares and five hundred ponies, they are all mothers and sons, so let's help the ponies find their respective mothers and their respective children." Remember, Da Lun, no one is allowed to make a mistake, if you make a mistake, I will severely punish you, as for the matter of my Tang princess marrying you Tubo, if Da Lun can't solve this problem for me, then don't mention anything about the marriage of the Tang princess in the future. ”

Lu Dongzan's brows furrowed suddenly, and the courtiers also talked endlessly. (To be continued.) )

PS: Two changes a day, from uninterrupted to the end of the book, I hope you will support a lot!