They are a teaching aid for showing students how the various planets revolve and rotate. With an Earth/Moon/Sun system model you can answer all these questions by just turning the handle.. 1  Why we have day and night. 2  What a year is. 3  What a lunar month is.  Why there is summer and winter.
Currency. Romania's currency is the leu (usually appears in the plural form lei). It comes in Polymer notes. The currency has changed to RON (Romanian new lei). 1 (green) 5 (purple) 10 (Reddish Brown) 50 (Yellow) 100 )Blue) (200 and 500 lei notes are rarely used). The leu's subdivison is the ban (plural form bani), 1 leu = 100 bani), which comes in 1 (brass), 5 (cooper) 10 (steel) and 50 (brass) bani coins.
2 non-European Union member states using the euro unilaterally (Kosovo and Montenegro). Romania is required by its EU accession agreement to replace the current national currency, the Romanian leu, with the euro, as soon as Romania fulfills all of the six nominal euro convergence criteria.