I believe only houston and Arizona have truly retractable roofs
No! They didn't have retractable roof stadiums in the 70s.
No, it does not have a retractable roof.
The weather, if the weather is bad they will close it like snow and heavy rain and thunder/lightning
Yep, some stadium have the roof for when its rain but some stadium doesn't roof so sometimes they post the game and the other they still play on the rain.
Yes The new stadium does have a retractable roof, but the old stadium did not.
Yes. The roof is retractable.
No it is a full dome but I do believe there new stadium will have a retractable roof
It has a retractable roof.
The Kingdome (which no longer exists) had a fixed roof. It was replaced by two stadiums, one for the Seahawks and Sounders (this is CenturyLink Field) and the other for the Mariners (this is Safeco Field). CenturyLink has roofs over the grandstands but none over the field. Safeco Field has a retractable roof.