In the answer sheet of this section, Lu Yu gave the method of resisting the invasion of the troops of the Tubo State and the Western Xia State was to dig more pits and build more fences.

The reason why Lu Yu would give the tactics of digging more pits and building more fences was also the "optimal" idea he calculated according to the characteristics of the armies of the Tubo State and the Western Xia State.

Lu Yu knew that the armies of the Tubo State and the Western Xia State were mainly light cavalry and had strong mobility, so the Song Dynasty army, which was dominated by infantry, could not be compared with it in terms of mobility, and it was more than six out of ten chips.

Moreover, the Song Dynasty did not produce good horses, and other countries did not sell good horses to the Great Song Dynasty, so even if the Great Song Dynasty intended to establish a light cavalry force to confront the Tubo and Western Xia light cavalry, it would be an absolutely impossible task, it was simply a fool's dream, so in terms of army attributes, the Great Song Dynasty was congenitally weaker than the Western Xia and Tubo.

Therefore, in every war with the Western Xia Kingdom and the Tubo Kingdom, even if the Song Dynasty has an absolute advantage in military strength, but what people play is the tactic of running after the fight, even if you have a lot of people, but you can't even catch up with other people's ponytails, how can you fight with others.

In addition to the violent mobility, the armies of the Tubo State and the Western Xia State also have another big feature, that is, they have no logistics troops and do not need to transport "military rations". the second is the "game" that comes from the bow and arrow at any time; the third is the aquatic products fished out of the river; Fourth, it is the "spoils of war" that have been snatched.

The Great Song Dynasty army, which mainly relies on eating food, can't learn from the nomadic army so "casual", the Great Song Dynasty army marches, and needs to recruit a large number of people to escort military rations, what is the speed at which the people transport military food, which is slower than the infantry of the Song Dynasty, so the Song Dynasty army, which cannot move without food, has to cooperate with the speed of the people's transportation volume to slow down their marching speed, so this military food problem also greatly slows down the mobility of the Song Dynasty army.

Therefore, there is only one way to fight with the light cavalry troops with strong mobility and the Song Dynasty, which cannot form a more powerful cavalry arm, that is, to limit the mobility of the opponent's cavalry.

Lu Yu came up with a way to limit the mobility of the opponent's light cavalry troops, is to dig pits and build fences, as long as the pit is dug deep enough, so that the war horses can't cross over, and the fence is built high enough so that the war horses can't jump over, and the entire battlefield is near the battlefield, with pits and fence walls to make it like a labyrinth, in that case, the so-called violent light cavalry troops are almost the same as infantry in terms of mobility, and the Song Dynasty army has the possibility of defeating them.

This set of "tunnel fence tactics" to restrict light cavalry, in Lu Yu's volume, has been written by him very clearly, after reading Lu Yu's volume Li Jing, also felt that his eyes lit up, after all, the current imperial court's method of dealing with the Tubo and Western Xia light cavalry is only to repeatedly build bunkers, and this method, although it can achieve some joint defense and restricted area light cavalry effect, but the pertinence is not strong, far less simple and direct than Lu Yu's method.

Moreover, the solution given by the county school students who are taking the exam is also to build a bunker, but they are entangled in the location of the bunker, as well as the number and density of the bunkers to be built.

"Teacher Hui......" After listening to the question raised by Li Jing, the "county school black boss", about the possibility of realizing the "tunnel fence tactics", Lu Yu replied softly with a wry smile: "If it is a student and I to implement this set of countermeasures, then the possibility of realizing this set of tactics is still quite high, but if it is implemented by others, then ...... It's hard to say...... Students don't dare to say that others are less capable than students, but ......"

"But what ......" While listening to Lu Yu's answer, he handed the scroll of Lu Yu's share of the strategy in his hand to his old nephew Li Fu's Li Jing, and raised his head and asked Lu Yu back.

"Teacher Hui, it's like this, for how to fight against the Western Xia Kingdom and the Tubo Kingdom, the students have been thinking about it for many years, so they came up with this set of tactics, about this set of tactics, over the years, the students have thought about the details and possible problems that can be thought of several times, therefore, the students dare to be, only the students and me, can the most perfect implementation of this set of tactics in the short term, and others, at least two to three years, can ......" After listening to Li Jing's interjection, Lu Yu explained to him in a whisper.

"Oh......" After Lu Yu finished explaining, Li Jing frowned and thought about it, about twenty or thirty seconds later, Li Jing nodded lightly and sighed: "What you said makes sense, indeed, doing anything is not achieved overnight, although your method is good, but the difficulty of implementation is indeed very high, if you want to build a fence and dig a tunnel through the state and the government, if you don't say anything else, those big manor owners will not agree, they will never allow others to mess around in their fields, convince them, it's a difficult thing......"

"Well......" After reading Lu Yu's volume, Li Fu, who was also shocked by Lu Yu's "whimsy", snorted lightly with his little uncle Li Jing after handing the volume to Zhou Ji.

After getting the volume, Zhou Ji unfolded the volume and reviewed it with Mr. Zhang Quanzhi, who was sitting next to him.

"How are you going to convince the big manor owners to allow you to dig holes in their fields?" Li Jing, who had been thinking silently for a long time, but didn't expect the slightest solution, frowned and asked Lu Yu.

"Back to the teacher, there is only one way, and that is - pros and cons, only when those big manor owners see the benefits of digging pits and building fences, and suffer the disadvantages of not digging pits and building fences, they will compromise and agree......" After listening to the teacher's question, Lu Yu bent down, leaned over to Li Jing's ear, and replied in a tone that only he and the "Four Heavenly Kings of County School" could hear.

"Hmph...... Good idea...... Don't get beaten...... How do you know the pain......" After listening to Lu Yu's "yin trick", Li Jing, the "county school black boss", directly praised the knot with his eyes shining, and then he sighed: "It seems that you have indeed thought a lot about this set of tactics, compared to others, you are indeed the best choice to implement this set of tactics......

After finishing speaking, Li Jing took a deep breath, and then, he slowly exhaled that breath, and his whole expression changed, as if he was "relieved", and then, he waved his hand and commanded Lu Yu loudly......