Ye Han was very satisfied with Luo Qi's creativity, and asked him to immediately organize people to do a few more, be sure to include all the base areas in the scope of monitoring, and arrange special personnel to monitor each listening box, so as to leave no dead ends.

Luo Qi immediately complied, and ran one battleship after another with a few soldiers, in order to enhance the monitoring effect, each battleship needed at least eight to ten listening boxes, which made him very busy for a while.

The ground listening box near the Jukai was the first to be put into use, and as soon as the soldier in charge of monitoring the radio turned up the radio in the listening band, he heard a dull explosion, and before he could come to his senses, it was again.

Only then did he remember that just now Ye Han seemed to have ordered to blow up the underground bunker inside the encirclement...... If the inside is not blown up, he will remember what the effect of this listening box is.

Although the situation was a bit unexpected, this soldier still reported the situation in time, letting Ye Han know that the listening box would not play a role for the time being.

Ye Han didn't pay much attention to it after receiving the report, but for the sake of prudence, he still ordered the whole division to be vigilant to avoid being attacked by the enemy.

The demolition operation in the encirclement was very smooth, the servants drawn from all directions began to advance inward, and immediately surrounded the underground bunkers on the way, and then the paratroopers who accompanied the operation started to blast open the chrysanthemum gate with a small amount of explosives, and then threw a large explosive bag into the hole.

If one of the explosives packets fails to blow up the hole, throw a few more into it until it collapses.

And instead of blowing up the hole in the ground and ignoring it, the servants who surrounded the hole did not withdraw, but continued to surround the hole and wait for orders.

In the process of advancing, it is not that there are no noble armies who come out to resist, but the diameter of the exit of the hole is limited, and three or five enemies are drilled out at a time.

After coming and going, the enemy simply did not come out, and let the coalition forces blow up the exits of the underground bunkers one by one, and after a while, all the bunker exits in the encirclement were sealed.

But this is not over, the aristocratic army's ability to make holes is too strong, there is no need to care about the exit or anything, as long as the noble army wants, it can make a new exit anytime and anywhere.

If you want to completely eradicate the noble army in the encirclement, you must use some special means.

So after the coalition forces blew up the last exit, the officer leading the team made a few gestures to tell the nearby servants to withdraw first, leaving about two squads of paratroopers to surround and seal the hole in the middle of the encirclement.

After the platoon commander who led the team waited for all the servants to retreat, he gestured to a soldier, who immediately took out a nuclear mine from his backpack, which was not much bigger than a plate!

He jumped to the bottom of the pit with the mine, carefully placing it at the bottom of the pit with an impossibly gentle movement.

As soon as the mine was dropped, the soldier jumped out and let out a sigh of relief and made an evacuation gesture.

The platoon commander immediately ordered the troops to withdraw, not just from this one hole, but with everyone.

The paratroopers who received the order immediately gestured to the nearby servants, and the men and horses on both sides quickly withdrew, and after everyone withdrew from the battleship, Ye Han gave the order to detonate.

A dazzling flash of light suddenly erupted in the middle of the encirclement, and then a ball of flame burst out in an instant, and the battleship shook together against the ground, throwing a huge amount of earth and gravel into the air.

The yield of nuclear mines is extremely small, only 12 tons at full load, but the power is really not small, and the thrown ore covers the entire battlefield after falling.

If Ye Han hadn't ordered the artillery truck and landing craft to hide well in advance, there would have been losses due to this small nuclear explosion.

The nuclear explosion came and went quickly, and after all the soil fell, a huge crater appeared in the middle of the encirclement, and although the underground situation could not be seen, it was certainly not much better, and I did not dare to say that the underground structure under the encirclement could be completely destroyed, at least the shallow passage could be destroyed.

Ye Han thought that the nuclear mine was easy to use, so he simply ordered the troops to put another one in the crater, if the enemy used the method of burrowing to sneak attack, then directly detonate this nuclear mine, and they couldn't kill them!

As soon as the order was conveyed, Ye Han received Luo Qi's report, the nuclear explosion was quite cool, but more than half of the installed listening box was damaged in the nuclear explosion, and only a few of the outermost ones were barely usable.

Ye Han hurriedly ordered Luo Qi to hurry up and repair it, and after thinking about it, he gave Luo Qi another hard beating.

The listening box is not a troublesome thing, as for the possibility of running with people? Directly hand over the method to the first and second regiments, and let them do it themselves, won't it be over?

So Ye Han gave another order, and after a while, all the listening boxes were placed, forming an invisible listening network.

The monitoring is not one person in each listening box, but the use of communication equipment to turn all the listening boxes into a whole, through the program to monitor all the listening nodes, any listening box found abnormal sound, will immediately trigger the alarm.

The time is too short for a special program for this set of equipment, but the listening box operates by sound, and the fleet is equipped with a batch of ultrasonic radars for cave detection in order to facilitate the attack on underground bunkers!

The working principle of these two devices is very similar, and the programmers accompanying the army, with the assistance of biochips, modified the receiving program of the ultrasonic radar, and used it on the listening network to a good effect.

But because the effect was so good, there were also a lot of jokes, first the sound of a few paratroopers landing touched the alarm, then the pace of two servants carrying ammunition in the bottom of the battleship triggered the alarm, and then I don't know what fell to the ground, triggering the alarm again.

The successive accidents were nothing short of torture, and the technicians were not allowed to urgently modify the procedures, try to filter out the noise from the paratroopers and servants, and do their best to avoid false alarms.

There is nothing difficult in modifying the program, whether it is footsteps or other noises, there is a fixed sound frequency, as long as the program ignores the frequency of the noise.

As soon as the programmer filtered out the footsteps, he suddenly heard a sound like scratching the wall in his ears, the sound was weak and continuous, which immediately attracted the attention of the programmer.

Through the cross-detection of the listening nodes, it was finally determined that the sound came from a depth of more than 40 meters, and it was likely to be the sound of the enemy digging a landslide!

Probably because the sound was too weak, it didn't even set off the alarm!

This is not good news, the programmer hastened to increase the sensitivity of the monitoring network, but due to the relatively high depth of the sound source, it should not be a precursor to the attack, the programmer recorded the frequency of this sound, and set it as the key monitoring frequency.

As soon as the programmer finished setting, the monitoring network sent out an alarm again, and several people thought it was accidentally triggered, so they opened the monitoring record and planned to load the frequency into the filter band, and the programmer in charge of filtering suddenly found that the sound source came from outside the encirclement!