A:文化环境决定着人们的价值取向
B:一定的文化环境中只能产生一种思维方式
C:不同的文化教育环境影响人们在实践中目标的确定和行为选择
D:美国人的思维方式比中国人的思维方式优越
(Ⅰ)求实数a的值;
(Ⅱ)证明:函数f(x)在区间(0,+∞)上单调递减.
-- Where's Mr Yu, do you know?
-- Well, it's hard to say. But I heard him loudly here just now.