On Portuguese prepositions, I can't get it to turn gold but when I click on it, it says the strength is 5/5.
Would you please let us know what operating system and browser you're using? (For example, I'm using Windows 7/Firefox). You can add this information by editing your post. This will help the tech team investigate what's going on. Thank you!
Also, while I'm not on the tech team, I wanted to ask if you have cleared your internet browser's cache and refreshed the page? Give that a try. If it works or not, please let us know. Thanks again!