If air-conditioner hadn't been invented in 1902,
...
If the airplane hadn't been invented in 1903,
...
If paper hadn't been invented in the 2nd century, ...
?
If the PC hadn't been invented in 1970s,
...
If the telephone hadn't been invented in 1876,
...
If electricity hadn't been invented in the late 19th century, ...
?
If the fridge hadn't been invented in 1850s,
...
If vaccination hadn't been invented in 1796,
...
If the Internet hadn't been invented in 1960s,
...
If photography hadn't been invented in the early 19th century,
...