Les niveaux de connaissance en langue ont été classés et définis par le Conseil de l'Europe. Cette norme européenne, appelée cadre européen commun de référence, est acceptée et reconnue dans tous les pays de l'Union Européenne. Elle détermine précisément les compétences que doit posséder l'apprenant pour communiquer dans certains contextes.
In May 2000 an international team of scientists witnessed the birth of a volcanic island in the Pacific Ocean, near the Solomon Islands. The underwater volcano Kavachi, which had been dormant for over nine years, started erupting.
Molten ash shot 500 metres into the air every five minutes and formed a beach just above the surface of the sea. The scientists were able to get to within 750 metres of the volcano and they filmed the eruptions over a period of 20 hours. They were extremely lucky because an event like this is very rare.