A:0
B:2
C:4
D:14
摄氏温度与热力学温度的关系为( )
These animals are in danger.We should think ______ to protect them.
设数列{an}的前n项和为Sn,已知数列{Sn}是首项和公比都是3的等比数列,则{an}的通项公式an=____
化简 =____