Arrange the events that led to the reunification of Germany in the correct sequence.

There is one step missing and it is;
US president Ronald Reagan delivered a famous speech challenging Soviet leader Mikhail Gorbachev to tear
down the Berlin Wall.
Answer:
The events from first to last are presented below.
Explanation:
Looking at the image, the events from first to last are;
The first event was: The Soviet forces constructed the Berlin Wall to prevent the escape of East Germans into West Germany.
The second event was: US president Ronald Reagan delivered a famous speech challenging Soviet leader Mikhail Gorbachev to tear down the Berlin Wall.
The third event was: Newly independent Hungary opened its border with Austria.
The fourth event was: East German leaders gave orders to open the gates of the Berlin Wall.
The fifth event was: The representatives of East
and West Germany signed the Reunification Treaty.