小明于2014年6月21日(夏至日)这一天进行了“立竿见影”的探究活动。读图回答:
从日出到正午,竹竿影子长度的变化规律是( )
A:逐渐变短
B:逐渐变长
C:先变短再变长
D:先变长再变短
— How many ________ were on the bus when the accident happened?
— About forty. Seven of them were kids.
设{an}是公比为正数的等比数列,若a3=4,a7=64,则a8=( )