Zhou Chen kills the two-winged stinger and completes the F-level hell difficulty task 'Counter Battle', and the system rewards a D-level synthesis blueprint -

【Burst Arrow】

Grade: D-Class Normal

Materials required: alloy (can be replaced) + 10 kg nitroglycerin + 500 g cotton + 1 kg of nitric acid + 30 energy points

……

This is the first time Zhou Chen has gotten a D-level weapon blueprint, although the level is not high, but the power is enough to kill ordinary bronze-level monsters in seconds.

What gave Zhou Chen a headache was that the energy required to synthesize D-class props was too high, and the materials were difficult to find.

"Nitric acid is an acidic corrosive product, that is, a strong acid, which is an important chemical raw material, and also a conventional prohibited product, which cannot be purchased by individuals, and there are few sellers, so you can only go to a professional chemical store, and I heard that there is a chemical store in the north of the survivor, and I don't know if there is nitric acid in it."

Zhou Chen thought as he walked.

He didn't expect to collect all the materials needed for the Burst Arrow at once, but he had to get at least one or two.

At the moment the most likely to get - cotton, alloys, nitric acid.

As for nitroglycerin, it's a matter of chance.

This thing is a liquid, which is a chemical hazard and will explode due to vibration, which means that it is flammable and explosive, and it is a good material for liquid bombs.

Because nitroglycerin can be used as a reliever for angina, some pharmaceutical companies have it in stock.

That's right, used to make bombs, flammable and explosive, very dangerous, the chemical nitroglycerin can relieve angina.

Chemistry is so magical!

If it weren't for Zhou Chen's curiosity and reading relevant reports, he might not have even heard the name nitroglycerin.

After all, he is a science student majoring in mechanical engineering, and he is also a science major, and the mechanical major and the chemical major are incompatible.

Zhou Chen went all the way north.

A small group of monsters was wiped out by him, and when he passed by that block, he found dozens of monster corpses missing, not even bones left, only large patches of blood and one dented road after another, telling that there had been a fierce battle here.

"Virus infections have too good appetites, eat meat, eat bones, eat metals, and may eat grass in the future, and even eat soil to evolve."

Zhou Chen sighed secretly.

The more I thought about it, the more I felt that it was difficult to survive and I was depressed.

Walk cautiously and alone along the way, killing dozens of black iron-level virus infections and avoiding several bronze-level monsters.

He is now qualified to fight a bronze monster for a second or two, but that doesn't mean he can kill a bronze monster.

Once the hard force fails, the mutation ability 'overclocking' greatly consumes physical energy, and when you encounter a black iron-level monster, you will be in danger.

"Still weapons don't work, if you have a D-class weapon......"

Zhou Chen is even more eager for the Burst Arrow!

Another half an hour of fumbling.

"The intersection, the huge street lamp, it should be here."

Zhou Chen came to the area around the chemical store that the survivors had said.

After a careful turn, he finally saw the chemical store with the door closed.

"Found it!"

Zhou Chen trotted over.

At this moment, he felt a small movement not far behind him, as if something was crawling against the ground, quietly approaching.

Zhou Chen Huo Ran turned around and saw a black black iron-level giant python with cold eyes slowly swimming in the S-shape, trying to assassinate him.

After the black python was discovered by him, it suddenly accelerated, opened its blood basin and bit it widely.

Zhou Chen was not afraid at all, as fast as lightning, he kicked the giant python in the jaw, kicking the small half of its body up one floor high.

Brush!

A sword stabs!

The bone sword entered through the jaw of the black python and came out on top of its head, piercing its head.

Draw your sword.

Suffering from this fatal injury, the black python did not die immediately, and attacked Zhou Chen like crazy, and was dodged by Zhou Chen.

After a while, the python stopped, turning into a corpse with only nerve reactions left, and the thick body of the grinding disc twisted and shook from time to time.

"Finally met a normal python, no longer a virus infection."

Zhou Chen dug out the heart and snake gallbladder with a happy face, and then peeled off the whole snake skin.

Store the snake gall and keep it for later to make the Alienation Pill, and combine the entire snake skin into a concentrated material, which is a strategic material that is used to repair armor during battle.

The heart and snake meat are synthesized to create several E-grade rare active snake meatballs.

Zhou Chen was surprised: "Isn't it a boutique?" ”

If you think about the strength of this python, it's not surprising that it's not a boutique.

Put the active snake meatballs into the light feather backpack, because the temperature is too high to store meat, a pile of black iron grade snake meat on the ground can only be discarded.

Zhou Chen walked to the window of the chemical store and looked inside.

It was empty, with an area of more than 100 square meters, and rows of blue shelves were neatly arranged, with various commodities large and small.

Zhou Chen swung his sword to cut the window security net, opened the window and jumped in, picking up one product after another in front of the rows of shelves, looking for nitric acid.

After two or three minutes of effort, Zhou Chen's eyes lit up.

"Found it!"

He was holding a black, hermetically sealed tin can.

This is an arm-high cylinder, specifications: 2.5 kg per bottle.

Just in case, Zhou Chen used the identification skill.

【Nitric acid】

Grade: None

Properties: strong acid

Introduction: A common chemical raw material, easy to decompose when seen in light.

……

It works!

Zhou Chen swept the nitric acid off the shelves.

A total of five bottles, ten kilograms.

"That's it?"

Originally, it was too little, but after thinking about it, ten kilograms is enough to make ten burst arrows, and one burst arrow consumes thirty points of energy, and ten is three hundred points.

In this way, I suddenly felt that ten kilograms is a lot.

Zhou Chen stuffed five large bottles of nitric acid into his backpack and jumped out of the store through the window.

All the way to the low-key, safely with the two teammates.

Zhang Yufei lay on the sofa in the living room with a big grin and asked, "Has the industrial expansion agent been done?" ”

Zhou Chen made an OK gesture to him and threw Lin Wanyi a sheathed straight-edged Tang knife.

After Lin Wanyi took it, she couldn't put it down and stroked the scabbard, looked at it over and over again, and after that, she pulled out half of the straight-edged Tang knife, and the E-grade boutique white bone knife was cold and dazzling.

"Thank you~"

——

Early the next morning.

"How does it feel?"

"It's okay, the combat effectiveness has recovered ninety percent."

Zhou Chen and Zhang Yufei had a brief conversation, and then turned their heads and asked Lin Wanyi: "What about you?" ”

"Peak condition."

"Let's go!"

The three of them went out.

It took two days to walk through the suburbs to a county seat.

Zhou Chen told the news from the survivors: "There is a chemical factory on the outskirts of the county, let's go in and have a look when the time comes." ”

"Chemical plants?" Zhang Yufei was puzzled: "What are you doing there?" ”

"Find a chemical material, nitroglycerin."

"Nitroglycerin? Damn, this isn't a liquid bomb! ”

"That's right!"

It took the three of them four days to cross the county and finally arrived at the chemical plant.

At the same time, Lin Wanyi successfully advanced to the one-star strengthening of black iron, Zhou Chen's seven-star strengthening of black iron, Zhang Yufei did not pick up the soul of the monster, and his combat effectiveness did not change.

Entering the chemical plant area, the three of them felt a depressing atmosphere.

Zhou Chen reminded in a low voice: "There are bronze-level monsters in the chemical factory. ”

Zhang Yufei and Lin Wanyi's hearts were cold, and their scalps were numb.

The last time I fought a bronze life, I remember the tragic scene.

Zhang Yufei couldn't help but say: "Let's avoid this aura and find a survivor to ask, if you don't have what you want, go directly, how about it?" ”

"Just what I want!"