问答题 Competition protects the freedom of the individual by ensuring that there is no monopoly of power.In contrast to one, all-powerful government, many businesses compete against each other for profits.

问答题 The two leaders already met once over diner Monday night, shortly after Obama arrived in the frigid Chinese capital from Shanghai.National security adviser James L. Jones described that meeting as an "informal diner discussion" in which the two leaders discussed "the evolution and histories of China and the United States".

问答题 Obama also called climate change and nuclear proliferation "challenges that neither of oar nations can solve by acting alone".He said the two will continue to "build a positive, cooperative and comprehensive relationship".