1. What was scientists understanding of methane?
A h was produced from plants.
B It was not a greenhouse gas.
C It was produced in oxygen-free environments.
D It traps more heat than any other greenhouse gas.
2. To test whether plants are a sot,roe of methane,the scientists created
A a oxygen-free environment.
B an environment with the same concentration of oxygen as the Earth has.
C a carbon dioxide-free environment.
D an environment filled with the greenhouse gas.
3. Which statement is true of the methane emissions of plants in the experiment?
A The lower the temperature,the higher the amount of methane emissions.
B I.iving plants release less methane than dried plants at the same temperature.
C When exposed to sunlight,plants stop releasing methane.
D The higher the temperature,the greater the amount of methane emissions.
4. Which of the following about methane is Not mentioned in the passage?
A Plants growing in soil release methane.