A:To her much disappointment
B:To her great disappointment
C:Great to her disappointment
D:To her disappointment much
图中,是一定质量的水,体积随温度变化的图象。由此可知在严寒的冬天,河面封冻,较深的河底水却保持____的水温,鱼儿仍然可以自由自在地游,而冰层下接触冰的水的温度却是____℃
已知函数f(x)是定义在(﹣∞,+∞)上的增函数,且对任意的实数x,y都满足f(x+y)=f(x)+f(y),f(2)=1.
(Ⅰ)求f(1);
(Ⅱ)若f(x)+f(2x﹣1)≤2,求x的取值范围.