They provide us with food, wood and most (important), oxygen.
举一反三
- 往下猛拉氧气面罩让他开始充气。 A: Pull the oxygen mask with a continuous movement to start the flow of oxygen. B: Pull the oxygen mask with a gentle movement to start the flow of oxygen. C: Pull the oxygen mask with a sudden movement to start the flow of oxygen.
- Nitrogen and oxygen are ___ important ___ most living organisms cannot survive without these elements.
- 突然拉下氧气面罩，启动氧气流动 A: Pull the oxygen mask with a sudden movement to start the flow of oxygen. B: Jerk the oxygen mask to start the flow of oxygen.
- The most important material used in ancient architecture is _____. A: soil B: wood C: rock D: tile or cement tile
- Wheat is one of the most important food crops in China, which is mainly used in industry.