____
Last night, he didn't sleep until 11 o'clock.
在样本的频率分布直方图中，共有9个小长方形，若第一个长方形的面积为0.02，前五个与后五个长方形的面积分别成等差数列且公差是互为相反数，若样本容量为1600，则中间一组（即第五组）的频数为____
As soon as he got home, it began to p____(倒；灌) outside.
