Because the matter is more complicated and the project is relatively large, in the end, I found the major ministers, the prince discussed, and finally got the approval, and also cooperated with the public, and began to prepare for the implementation of this huge project of south-to-north water transportation.

The river was finally built for six or seven years before it was repaired, because the project was huge, and Du Xi'er was scolded for being miserable in the years of construction, but the convenience brought by the completion of the construction benefited the people, and finally everyone praised Du Xi'er, of course, this is all later.

When everyone stepped back again, Yan Ao'an seemed to be even more curious when he looked at Du Xi'er, what a crazy person this is, like a lady?

Du Xi'er has been waiting for Yan Aoliu to come back, but it wasn't until dark that Yan Aoliu came out of the palace, Du Xi'er waited for Yan Aoliu to come back and eat together, but the food was cold.

After eating, Du Xi'er seemed to think of something again, and immediately asked Xiaohe to bring what she wanted.

Yan Aoliu looked at the bamboo tube in front of him, as well as dirty mud, stones, sand, cloth, bamboo grass, ash, dirty water and other things, and fell into deep thought.

"What are you going to do?"

"What kind of expression do you have, look at it, I'll show you."

Seeing Yan Aoliu's disgusted expression, Du Xi'er was very angry, but she didn't really stop not getting it, but put the cloth at the bottom, put sand, grass, plaster, soil and stones into the bamboo tube, and then poured the mixed water into the bamboo tube, and soon, the clear water slowly flowed out along the bamboo tube, completely missing the mix at the beginning.

"Xi'er, what is the principle of this, how did you do it, do you have a spell?"

Seeing Yan Aoliu's look of admiration, Du Xi'er didn't know what to say, and then thought for a while before slowly speaking: "First, this is not a spell, and second, this can be called a simple water purification filter, and the principle is what you just saw." ”

Seeing that Yan Aoliu was fascinated by what he heard, Du Xi'er wanted to continue to explain: "If there is a flood, there will definitely be many deaths, and the water source is not clean, drinking unclean water is far more likely to get sick, especially easy to infect with plague, etc., so you must remember not to drink dirty water outside, and this water will be cooked after simple purification." ”

"Okay, don't worry."

Du Xi'er's explanation, Yan Aoliu remembered every word in his heart, and then began to observe and fiddle with Du Xi'er's simple water purification filter, this thing is simple and easy to do, but it will help Yan Aoliu a lot, whether it is this flood or the march on the battlefield!

"Xi'er rest early, Mo Qing and I will go to prepare some things for tomorrow's departure." Saying that, Yan Aoliu was about to leave.

"I, I'm actually ready for you."

Yan Aoliu looked at Du Xi'er with a surprised expression, and even wanted to see through a hole in her face, so she spent the night with curiosity and anticipation.

The next day, Yan Aoliu set off very early, Du Xi'er was still sleeping, so he didn't bother Du Xi'er, but he was excited to see Du Xi'er's luggage for him.

Several carts of things, including clothes and medicines, and even pots and pans were prepared for him, Yan Aoliu was angry and funny, and finally let people get these things out of the envious expressions of Fang Qingsheng and others, and finally only brought some of his change of clothes, as well as medicines, and finally he actually found his armor in a box.

Tears of emotion were instantly left in her heart, if it weren't for the fact that Du Xi'er was still sleeping, afraid of disturbing and waking her up, Yan Aoliu couldn't help but want to rush back and kiss her and hug her.

In the end, Yan Aoliu rode on the hurricane with his long-sealed armor, and left with the large army, Du Xi'er woke up and saw a bunch of things left by Yan Aoliu, and immediately wanted to scold Yan Aoliu for not knowing what to do.