Himekishi ga Classmate Isekai Cheat de Dorei ka Harem - Chapter 44Vol 2 .1

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

The next morning, Jian Anning asked, “What is happiness?” Yu Xingxing hooked his lips into a smile and suddenly pulled her into a tight embrace. “Happiness,” he said, “is being with the one you love and doing things that make you happy. Let's continue, wife!” Jian Anning kicked him off. “Get lost!”

In this world, being a farmer is a noble profession.

To obtain the Zhang Xiaofan super ability, have no matter all sorts of grass, raise flower, you ‘ll became one big guy unconsciously.

At a dying grass, give it 60 points of life, and will live.

Villain holding a 100 years of Lingcao in front of Zhang Xiaofan show off in an ostentatious manner, conveniently give it a year. As a result of the tragedy, it degenerates into a ten rank grass, the villain be crying faint in the toilet.

- Description from Novelupdates