【单选题】听力原文: (32)I am optimistic by nature. I am glad that I am alive. I am glad that I am living at a very difficult, very dangerous, and very crucial period in human history. I support my optimism with my ...
A.
Her happiness to be alive.
B.
Her happiness to be close to nature.
C.
Her optimism about how much knowledge she can gain.
D.
Her optimism about the future of mankind.