It is reported that atmospheric carbon dioxide is currently at its ______ level in the history.
A: Higher.
B: Lowest.
C: Highest.
D: Lower.
A: Higher.
B: Lowest.
C: Highest.
D: Lower.
举一反三
- A tax placed on a product causes the price the buyer pays A: . and the price the seller receives to be higher. B: . and the price the seller receives to be lower. C: . to be lower and the price the seller receives to be higher. D: . to be higher and the price the seller receives to be lower.
- The aged population is currently at its highest level in human history. The United Nations predicts the rate of population ageing in the 21st century will exceed that of the previous century.
- What will the newly-launched observation satellite do? A: It will record carbon dioxide emissions and absorption worldwide. B: It will identify carbon dioxide emission sources with higher efficiency. C: It will monitor carbon dioxide levels in Earth’s atmosphere. D: All of the above.
- The melting point of uranium dioxide is plutonium dioxide A: higher than that of B: the same as C: lower than that of D: similar to
- The higher the threshold, the higher the tissue excitability () A: The higher the excitability B: The lower the level of excitement C: The higher the level of excitement D: The less excitability E: No excitability