[填空题]The human brain can do a lot of wonderful things; many of them include 　1　 mastery of complex feedback systems with long 　2　 For example, consider how difficult raising a child truly is. Many factors are 　3　 , including the nutritional, physical, emotional and mental condition of the child, and the feedback of these factors 　4　 the behavior of those involved in raising the child. To 　5　 matters, many of the responses of the child/parent "system" take years to 　6　 themselves. Yet billions of parents have somehow 　7　 to feed, clothe, protect, nurture, heal, teach, and love their children 　8　 successful adulthood. 　　 　9　 all our intuitive sophistication in dealing with complicated situations, it’’s a 　10　 to see how poorly we deal with some newer systems, most of 　11　 brought about by technology. 　　Both raising children and protecting Earth’’s life-support systems are 　12　 of life and death; in the long term, they are equally important. But 　13　 our brains seem fairly well prepared for
A. A．complicate
B． confuse
C． contrive
D． complement