the US decide to drop two atomic bombs on Japan, not china
The US has dropped atomic bombs in 1945 on two Japanese cities, Hiroshima and Nagasaki.
Hiroshima, Japan
sure?
The USA only had 2 atomic bombs.
Hiroshima and Nagasaki
They did not, it was the other way round.
No, the Japanese military did not drop any bombs on the USA after the atomic bombs were used on Japan. The bombs and pending invasion by the Soviets and the Americans (and allies) motivated the Emperor Hirohito to surrender to the Allied Forces.
Noplace, the US did not have any atomic bombs in 1944. Nobody had atomic bombs in 1944.
Japan never dropped the atomic bomb on anyone. They did not have that technology.
The cities were called Hiroshima and Nagasaki. The US dropped the atomic bombs onto Japan on August 6th and 9th 1945.
If you are referring to WW2, then the US stopped using atomic bombs on Japan because Japan agreed to surrender. Had they not, the US had plans and production setup to drop a total of 23 atomic bombs on Japan in 1945.