Các câu ví dụ cho từ oxygen

1. Sherpas, high altitude guides and workers drawn from the indigenous local ethnic group, carry heavier items including tents, extra oxygen cylinders and ropes up the mountain - and then down again.

2. As rising numbers of coronavirus infections worry the population, some decided to purchase ventilators and oxygen tanks themselves as a precautionary measure.

3. The report in Proceedings of the National Academy of Sciences says the moss mantle began to proliferate about 470 million years ago, providing our planet with the first stable source of oxygen and enabling intelligent life.

4. ""Our study shows that the earliest land plants were amazingly productive and caused a dramatic increase in the oxygen content of the Earth's atmosphere.

5. " oxygen first appeared in Earth's atmosphere about 2.

6. But oxygen didn't reach its current levels until about 400 million years ago.

7. Some scientists have theorized that forests increase oxygen levels, but the PNAS study disagrees with that view.

8. Using computer simulations as a way to peer into the past, the researchers estimate that lichens and mosses could have produced about 30 percent of the oxygen on Earth around 445 million years ago.

9. As moss proliferates, it increases the amount of organic carbon in the sedimentary rock, increasing the oxygen concentration in the air.

10. This oxygen boost "allowed large, mobile, intelligent animal life, including humans, to evolve", the study says.