[问答题]
(a) Compare the energy needed for the first 7wxh*ir ;b xvwe0.nj2rea eoloa 2ks)zk)7u +l)mction of the carbon cycle to that o2ka klez)+ uo)l)7msfor a deuterium-tritium reaction.
(b) If a deuterium–tritium reaction requires $T \approx 3 \times 10^8\ \text{K}$, estimate the temperature needed for the first carbon-cycle reaction.
