Yoghurt contains living bacteria. Bacteria are also capable of anaerobic respiration. If a sealed carton of yoghurt is left for a long time, the lid bulges upwards. Why does this happen?

The bacteria is expanding underneath the surface of a container that is sealed, also the bacteria is spreading so it makes more room
by pushing the lid upwards

The truman doctrine was an american foreign policy whose stated purpose was to counter soviet geopolitical expansion during the cold war. it was announced to congress by president harry s. truman on march 12, 1947, and further developed on july 12, 1948, when he pledged to contain threats to greece and turkey