"If Amundsen hadn't managed to reach the South Pole in 1911, Antarctica wouldn't be one of the most important sites for cutting-edge science nowadays."
- Justification: This is a second conditional sentence, expressing a hypothetical situation in the past (Amundsen not reaching the South Pole) and its potential consequence in the present (Antarctica not being an important site for science).
"So, if you decide to become a scientist, you will probably dream of going there one day to study the area and the effects of climate change."
- Justification: This is a first conditional sentence, presenting a possible future outcome (dreaming of going to Antarctica) based on the condition of deciding to become a scientist.
"If a holiday to Antarctica were cheaper, more young people would definitely go there."
- Justification: This is a third conditional sentence, discussing a hypothetical past situation (a holiday to Antarctica being cheaper) and its potential consequence in the present (more young people going there).