问题详情

In Paragraph 2, why does the author mention a jungle gym？
A．To show that chemistry elements take the shape of a jungle sometimes.
B．To indicate that there are many differences between chemistry and other fields.
C．To demonstrate that studying chemistry is very hard due to its indirectness and uncontrollability.
D．To indicate that it is very difficult to determine the arrangement of the atoms in a crystal.请帮忙给出正确答案和分析，谢谢！