A:农业文明
B:工业文明
C:知识经济
D:信息文明
(Ⅰ)求f(x)的单调区间;
(Ⅱ)若a=﹣1,判断f(x)是否存在最小值,并说明理由.
玻片上写有一“p”字母,在显微镜视野中看到的物像是( )
At the beginning of the 20th century, many people thought that the family was falling apart—__________, they thought it was dying. ( )