"This is an underwater dark hole, I think the legendary Xiantan must be here!" Fawn Road. Pen, fun, pavilion www. biquge。 info

I struggled to get up from the ground, rested against the stone wall next to me, eased my previous tension, and then asked him, "Why are you so sure?" ”

"Don't say it!" Lao Hai suddenly interjected, "This little brother is really a god, he actually knows that there is such a secret passage under this water!" Eh, tell me how you know! ”

Xiaolu smiled and said, "I stood on the bridge and looked down, and found that where the sun shines, the flow speed of the river has decreased significantly......"

"So what?"

"Because the width of the river has not changed much, the root cause is probably at the bottom of the river, and I wondered if it was a change in the depth of the river that caused this phenomenon, but I immediately realized that it was not possible!"

Xiaolu paused and continued: "Because the speed of the river is almost suddenly reduced, this means that there must be a certain height difference in depth to achieve such an effect, if the depth of the river bottom has changed suddenly, then over the years, it will definitely form a deep pool of falling water, and the width of the two banks will continue to increase, but there is no such topography on the site, so this possibility can be basically ruled out." ”

"So what's going on?" Lao Hai was puzzled, "Don't sell it, anyway, I can't understand a lot of it, let's have some fun!" ”

"Actually, at that time, I didn't know the specific reason, but I thought this phenomenon was very strange, and I guessed that there was something at the bottom of the river, so I had the mentality of giving it a try......

"Give it a try?!" Hearing this, I immediately sat up and said excitedly, "You want to give my life a try?" ”

Xiaolu hurriedly waved his hand to me and said: "Actually, I have a plan, although I don't know the specific reason, but I can be sure that it is a clue about Xiantan, if you don't jump, you will never find Xiantan!" If Lao Hai and I both jump, you don't dare to jump, no matter whether you find Xiantan or not, you will be separated from us, wouldn't it be more dangerous? ”

That's true for me when I think about it, but in any case, it's really dangerous.

"You go on!" I said.

"When we entered the water, I found that there was a reverse undercurrent at the bottom of the river that was similar to a tidal wave, and this undercurrent made us almost not wash away but continued to sink, and when we reached the bottom, I found this waterfall, which is also the root cause of the change in the flow of the river."

As he spoke, the fawn pointed to the big waterfall next to me, and I climbed over to look up, but because of the water vapor, I couldn't see what was going on above.

Xiaolu then said: "I saw it just now, in fact, this waterfall does not exist all the time, but has a certain period...... Because the velocity of the tidal undercurrent is small and the pressure is strong, the water will remain along the large hole above the head to form a waterfall, and when the velocity of the undercurrent becomes larger, the pressure decreases, and the flow rate of the river will return to normal. The reason for this change is the sun! ”

"The sun?" I couldn't understand it more and more, and Lao Hai was even more confused.

"The gravitational pull of the solar tide causes the water level to rise slightly, although the effect is very weak, but it can cause an undercurrent at the bottom of the river due to the vacuum phenomenon of the local flow layer, and this effect becomes more intense as the sun moves towards the center of the overhead, and this effect is strongest when the sun appears above the fissure, that is, when we saw the sun before, according to the principle I just mentioned, it will cause a sudden decrease in the flow velocity. Once the sun shifts at an angle, the tidal gravity weakens, the waterfall disappears, and the river's velocity returns to normal. After Xiaolu finished speaking, he took a big sip of water to moisten his throat.

Lao Hai and I were stunned for a moment, pretending to understand, and then nodded.

"It's a shame that you can't do anything else!" Lao Hai said with a smile.

"Actually, we are also lucky, just in time for this time, otherwise it would be impossible to discover the secret of the bottom of the river, if it weren't for the sudden appearance of the sun, maybe we would still be walking stupidly on the bridge now!" Fawn Road.

As soon as the words fell, the sound of the waterfall suddenly weakened, and as the flow decreased, the sound gradually disappeared, and at the same time, the waterfall disappeared, and soon we fell into darkness, unable to see any light.

"Looks like I'm right!" The fawn said confidently.

"Wow! What's going on? Why is it all black? Lao Hai exclaimed excitedly.

"When the waterfall disappears, the upstream river will carry sediment and silt at the mouth of the cave, covering the hole, so naturally there will be no light coming in!" Fawn explained.

"So, what should we do now?!" Lao Hai's voice seemed a little panicked.

Gada--The surroundings were lit up again, and a small flame flickered in the air.

"Huh? Where did you get this lighter? Lao Hai asked Xiaolu.

"I picked it up when I first came in, it should have been dropped here not long ago!" Fawn explained.

"Not so long ago? Could it be Li Wuchang and them? I asked hurriedly.

Xiaolu shook his head, thought about it and said, "It shouldn't be, although this lighter is waterproof, the water on it has dried up when I picked it up, and it is still covered with a thin layer of ash, at least left by someone a month ago." ”

"Someone came a month ago?" I felt a little incredible, "Who would come to this kind of place besides us and Li Wuchang?" ”

"Why won't anyone come? Isn't that Wu Kong who is with you looking for this place? "Fawn said.

I'm right when I think about it, although I don't know the specific situation of Xiantan yet, but I'm sure there will be a lot of people who come to look for it, Wu Kong and Yang Tianxia are the best examples.

We walked down the cave, and the more we got inside, the more we could feel a terrifying chill, and Lao Hai said that I was now underground, and I would definitely encounter something strange, so I had to be more careful.

The fawn stops and goes, because the quality of the lighter is not very good, it can't be ignited for a long time, and there are no decent wooden sticks around to make torches, so we can only stop and go, wait for the lighter to cool down, and then continue to move forward.

I don't know how long I walked like this.,A stone door suddenly appeared in front of you.,The stone door was open.,The machine key next to it has already been destroyed.,It seems that this door still has a mechanism before.。

We cautiously walked forward, came to the door and peeked in, and saw that this was a dim stone room, with a coffin in the center, four stone tomb beasts squatting in the four corners, and the wall next to it was full of murals such as dragon-patterned tigers and leopards, and in one of the corners there was a passage leading to the depths, which seemed to have no end in sight.

"W-This fucking burial chamber!" Lao Hai exclaimed.