"They eat and they drink."
Translation:Ei mănâncă și ei beau.
It could work here if you want to put emphasis on the different actions (eat vs drink).
We would surely say Ei mănâncă iar ei beau (but note that it's essential for this to make sense that the former ei are others from the later ei), but we would never say Ei mănâncă iar ei mănâncă.
what about Listen-option at https://translate.google.com/?hl=en#view=home&op=translate&sl=ro&tl=en&text=beau
It's perfect, thank you! I deleted the first link. And this is also a good idea for the other mispronounced words!
Iar is for a comparison, when you have 2 different groups that make 2 different actions. For example: "Ei mănâncă iar ele beau"
For the second part of your question, in Romanian the verbs must be conjugated according with the person. In this case:
I s - eu mănânc
II s - tu mănânci
III s - el/ea mănâncă
I pl - noi mâncăm
II pl - voi mâncați
III pl - ei/ele mănâncă