oxygen
/ˈɑksɪʤən/
a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust
中文释义：氧气；氧
Plants produce oxygen during photosynthesis, which is vital for animal life.
植物在光合作用中产生氧气，这对动物生命至关重要。
High-altitude climbers often carry supplemental oxygen to avoid altitude sickness.
高海拔登山者常携带补充氧气以避免高原反应。