After hearing Zhuang Zhou's words, Li Er's expression suddenly changed.

Obviously he had realized something.

He hurriedly urged:

"Brother Zhuang, could you please demonstrate it to me now?"

"Ah? This..."

Zhuang Zhouke is ready to return to the city.

After thinking for a while, he said, "Brother Qin, how about I show you how to do it when we get back to the city?!"

“Is there cement dust in the city?”

"Yes! The grocery store has everything."

Li Er couldn't help but exclaimed in admiration:

"Your grocery store is truly a magical treasure shop."

After chatting for a while, the three of them returned to the city.

Zhuang Zhou led the two of them directly to the backyard of the grocery store.

Then he took out a bag of cement and put it directly on the ground.

“Hey, this is cement gray!”

Looking at the snakeskin bag in front of him, Li Er was sure that he had never seen it before.

"Can you open it and take a look?"

"sure!"

After saying that, he was about to get the knife, and he saw the sword at Li Junxian's waist.

"Here, let's use your sword."

Li Junxian was still a little hesitant.

Such a good sword, use it to cut bags?

But he soon saw Li Er's eyes and hurriedly did as he was told.

The cement bags were separated, revealing the gray cement dust.

Li Er reached out and grabbed a handful:

"Why does this cement dust look a bit like gray flour?"

Li Junxian echoed:

"I think it's flour."

Zhuang Zhou smiled and said:

"This isn't flour. Strictly speaking, it should be called stone flour."

Zhuang Zhou briefly explained the production process of cement ash.

Then he found some wooden boards and iron nails to make a wooden box that was 30 centimeters long, wide and high.

The next step is to make cement mortar.

Similarly, mix cement, river sand and water, and then put it into a wooden box.

Then, Zhuang Zhou used a trowel to smooth the cement slurry on the surface.

"Alright! It's done!"

Although a little cement mortar was wasted, it allowed Li Er to show him a great invention of later generations.

Zhuang Zhou was still very happy in his heart, and said with a happy smile:

“This is cement mortar, and it’s very useful.

It can not only be used to build houses, but also to build bridges and roads.

You can also build city walls, which can be said to be indestructible..."

I haven’t finished speaking yet!

Then I saw Li Er stretched out his finger and poked it.

Then I saw a hole in the cement mortar.

Zhuang Zhou: “…”

Hello!

Could you please not be so naughty?