The well building only brought 15 contribution points to Gu Guo, after all, the well was a product of the Neolithic Age, and he only made it in the Bronze Age, and the gap in civilization directly reduced the system by half of the points.

But he doesn't have much to do with his contribution points now, as they can only be exchanged for copper and tin if they are currently used for metal, and he didn't need that much bronze before the population exploded.

Unless one day the system opens up the exchange of high-yield crops, Gu Guo can use the system to raise his eyebrows.

However, the system shop could only exchange for those things that Gu Guo had made, such as bows and arrows, clay pots, etc., and the era he lived in limited the items he could exchange.

Even if a piece of meteorite fell from the sky at this time, and Gu Guo picked it up and forged it into an iron tool, the system would not determine that Gu Guo was the ultimate influencer of the meteorite, and the nuclear fusion of the star was.

Therefore, the contribution point of the birth meteorite should belong to the sun in the sky instead of Gu Guo, and only when Gu Guo restores the iron element from the iron-containing ore, then the system will default to him as the ultimate influencer of iron, and the contribution point will be added to his head.

After sorting out this relationship, Gu Guo gave up running and entered the Iron Age, because when he was in the Iron Age, the contribution points obtained by all Bronze Age technologies would be halved, and the gains would outweigh the losses.

......

Spring River Plumbing Duck Prophet, there are no ducks in another world, but there is a white water bird with flippers.

The pale yellow beak of the waterfowl is holding an inch-long crucian carp, and the tip of the beak is red to make it stand out.

However, a huge splash of water on the shore startled the flock of waterfowl to drop the food they had so hard to find.

The sailboat was finally launched at the beginning of spring.

The 15-meter-long, 3.5-meter-wide ship was now docked on the shore, gently undulating up and down with the regular swaying waves.

From the upper deck, the nine-metre-high mast hung three huge sails, each as large as a wall in a house, and the people of the city had been busy all winter weaving these three hard sails.

The sparks that connected the masts cut through the early spring north wind, and the sound of the grinning wind echoed in the ears of the clansmen on deck.

The sailboat sailed for the first time on the Tao River, and drove a round trip on the Tao River, down the river and the acceleration of the north wind, which was several times faster than the birch bark boat, and much slower when going against the current, because the headwind needed to constantly adjust the sails to go zigzag, the sailboat went back and forth between the rivers, and the same distance, the return time was five times that of the downstream.

However, it is still much faster than walking.

Handing over all the matters in the city to his mother and Sang and others, Gu Guo took a dozen or so clansmen who would not get seasick, and sailed downstream with full sails, and the yellow-white sails were painted with red copper ore powder by him in a regular pattern, and this bright red triangular composition could be seen clearly from a hundred meters away.

It takes seven days to walk the Yangya tribe, and it only takes more than ten hours to arrive at full speed with a speed close to ten knots, but Gu Guo did not rush to sail at night, he is not familiar with the waters of the Tao River, in case he touches the bottom in the river in the case of black rumbling at night and knocks the boat out of a hole, it will really be called the heavens and the earth.

The pigskin lit an oil lamp, which is a small lamp made of animal oil mixed with fiber rope, and placed in a clay pot, the fiber rope is fixed in the center of the clay pot, even if the animal oil liquefies due to high temperature, the fiber rope will not pour into the oil and cause the flame to go out.

The bronze anchor held the sailboat more than thirty meters from the riverbank, and the currents at night were more turbulent than during the day due to the tidal gravity of the moon, but the people sat in this behemoth with a displacement of nearly twenty tons, as steady as an old dog.

The pigskin chewed on a piece of bacon, the grease reflecting the light on his lips.

"With this sailboat, the birch bark boat will not be exchanged for a few copper coins." (In winter, Gu Guo exchanged pottery money for copper money)

"Yes, with this sailboat, we can drag a very large net from the lower reaches of the Tao River all the way upstream, but unfortunately we can't weave such a big net, and the rope will definitely break."

Birch shook his head into a rattle and said firmly.

Gu Guo watched a few people silently on the side, expressing their opinions one by one, and occasionally guiding the direction of the topic.

It was late at night, and a dozen people lay on the flat plank beds below deck, while the lower compartment stored their men's survival supplies for two months, in addition to pickled jerky and fresh water, and a small amount of starch-rich tubers.

In bursts of earth-shattering snoring, Gu Guo fell into a deep sleep.

The next day, the morning sun rises on the other side of the Tao River, and the tribe of Yangya ushers in a new day. After the first "friendly" exchange with the Gu tribe, the Yangya tribesmen all moved out of the cave, learned from the upstream, and built more than 20 houses on the bank of the Tao River, but due to the lack of manpower and tools, the city wall that Yangya had in mind showed no signs of breaking ground.

Black Tao, who was fetching water by the river, lifted the pot and found a strange thing floating down from the upper reaches of the Tao River, above the water was a house made of wood, and on the top of the house, a straight tree trunk hung a cloth on three sides that was larger than the mouth of the cave where he once lived.

"This ...... What is it? ”

Black Tao exclaimed, and several of his fellow clans on the shore also spotted the behemoth on the river, the front of the giant broke through the waves, and the white water foam pulled into a long trail behind it.

"Look at the pattern on it!"

The sharp-eyed clansmen found the pattern at the top of the sail, and Hei Tao recognized it at a glance as a tool handed down from the Gu tribe.

Rules and regulations!

That tribe upstream had built such a huge ship!

Gu Guo, who was standing on the deck, asked the sail to put away the sails, and only relied on the power of the current to propel the sailboat forward, he wanted the people of the Yangya tribe to appreciate the advanced masterpieces upstream.

"Are they going to land?"

One person looked at Hei Tao in panic, he was one of the people who had been reformed through labor last time, and seven consecutive days of digging dung gave him a shadow on Gu Guo's tribe.

"It should ...... No, they're still a long way from the shore. Black Tao swallowed, and the crowd was shocked by the sailboat they needed to look up to, and not a single one ran back to report the news.

Gu Guo stood on the right deck, looking at the panicked appearance of the group of people on the shore, and couldn't help laughing.

"Last year I was worried that there would be a tribe in the south that would be stronger than us, but now this group of people needs to look up at us." Gu Guo said with a smile.

The pigskin on the side nodded, their destination was not the "close" Yangya tribe, but the wider world in the lower reaches of the Tao River.

The sailboat went from appearing in Hei Tao's field of vision to disappearing into the mist of the lower reaches of the Tao River, but in just ten minutes, it made Hei Tao's group sit like pins and needles.