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

(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 knowledge of how far mankind has come. Throughout the hundreds of thousands of years that human life has evolved, at first physically and later culturally, human beings have withstood tremendous changes and have adjusted to radically new demands. (33) What we have to realize, I believe, is that human ingenuity, imagination, and faith in life itself have been crucial both in beginning changes and in meeting new demands imposed by change.
(34)As an anthropologist, I also have seen bow a living generation of men born into a Stone Age culture has moved into a modern world all at once, skipping the many small steps by which mankind as a whole moved from the distant past into the present. I find these things encouraging an earlier generation invented the idea of invention. Now we have invented the industrialization of invention—a way of meeting a recognized problem by setting hundreds of trained persons together to work out solutions and, equally important, to work out the means of putting solutions into practice. This is what made it possible to send men to the moon and to begin the exploration of outer space. (35)This should give us reason to believe also that we can meet the problems of over population, war, and the pollution of the earth on which we depend for life. All of these problems can be solved. What we need is the will to demand solutions and patience to learn how to carry them out.