Benjeto is an Esperanto word, but it means 'beignet'--not exactly 'donut'. The Plena Ilustrita Vortaro mentions ringoformaj benjetoj 'ring-shaped beignets', which is a bit more specific. I would probably just call a donut a benjeto, but I don't know what other Esperantists tend to do here.
When I checked on Google Translate, I got benjeto rather than beneto--which is good, since as Chuck mentioned, beneto means 'small blessing'. But although it was accurate with this particular word, don't trust Google Translate for Esperanto! Try using Wiktionary, Reta Vortaro, or the dictionary at lernu.net (which you can find on the right side of the page).
As long as I understand, the language doesn't express the difference unless it's absolutely needed. However, if it's really needed, you could say something as "The police officers use to drink coffee" and "Now, the police officers are drinking coffee". Most languages I know do that.
This page does not show the answer properly. Sometimes when submitting the correct answer, minor errors are overlooked. However, in order to further inspect the "correct" answer, I have to navigate to the "discuss" page. This is not always the case. Most exercises do show the answer to inspect after submitting (whether you are marked right or not).