"Candour" means ______.

A．show the inherent weakness of the greenhouse effect theory
B．show that the greenhouse effect works on other planets but not on the earth
C．show the extent to which Earth's atmosphere differs from that of the Venus
D．supper the argument that the CO₂ level in the atmosphere has a significant effect on climate

A．Why are projections of the effects of changes in water vapor levels on the climate so inaccurate
B．What are the steps in the process that takes place as CO₂ absorbs long-wavelength radiation
C．How might our understanding of the greenhouse effect be improved if the burning of fossil fuels were decreased
D．What might cause a series of regular increases and decreases in the amount of CO₂ in the atmosphere