ich ben Fortschritte machen auf Deutsch

[Ginger_Fi]

---Hey Renate! I know in the grand scheme of things it's not a big deal but..... I translated my first English to Deutsch sentence correctly.
--- The sentence was "One apartment doesn't have a kitchen"
--- My answer was "eine Wohnung hat keine Küche"
---My book said I was right. Please feel free to correct it if the book was wrong

[Ginger_Fi]

Also I have two questions about proper sentence structure.
Two other answers I wrote, I think I am right, but the book says I'm wrong.
1: "Der Sohn ist Elektriker" -or- "Der Sohn ist ein Elektriker"?
2:"Das ist auch ein Problem, aber der Vater installiert ein wassersystem" -or- "Das ist auch ein Problem, aber der Vater installieren ein wassersystem"
In both instances my answer was the second one, and the books answer was the first.