把3.1缩小到它的1100是0.031,
故答案为:1100.
“|x-1|<2成立”是“(x+1)(x-3)<0成立”的______.(请在“充分非必要条件”、“必要非充分条件”、“充要条件”、“既非充分也非必要条件”选择一个最恰当的结果填在横线上)
Summer is coming. The days are getting _ . [ ]
A. long and long
B. long and longer
C. longer and longer