Isn't it kind of obvious that if the door is closed, people don't usually want to be disturbed (at that time)?
こんにちは！
ご質問ありがとうございます。
"Isn't it kind of obvious that if the door is closed,"＝「もしドアが閉まっていたら、かなり明白じゃない?」
"people don't usually want to be disturbed (at that time)?"＝「普通、人々は(そのときに）邪魔されたくないということが。」
ご参考になると幸いです。
Normally, when a door is closed, you would assume that they wouldn’t want you to come in.
"普通ドアが閉まってたら入って来てほしくないって分かるやろ"
- Normally, when a door is closed, you would assume that they wouldn’t want you to come in.
- You know, most people wouldn’t come into a room when the door is closed.
- Usually when a door is closed, you would know that the person inside wouldn’t want you to come in.
アメリカ合衆国 
