Big Country 1977: a Female Educated Youth Exchanges Marriages and Rubs Rocket Launchers with Her Hands

[Great country's military industry + era + system + technological power] Li Beicheng, a scientist in the previous life, was betrayed by his younger brother and was assassinated by foreign forces. After waking up, he found that he was back on the day of his wedding. However, this time his younger brother Li Yongfu actually offered to trade with him for a place in the arsenal. Only then did Li Beicheng know that his younger brother had actually been reborn. After entering the arsenal, Li Yongfu continued to come up with black technologies that surpassed the times... China became the world's leading military power! And when Yingjiang woke up from his sleep: I reported Rabbit for cheating!