A1=2,A2=3,A3=A1A2,A4=A1A2A3,…,若Ant=(n≥3),那么An+2=
参考答案:t4
He____ as a national hero for winning the first gold medal for his country in the Olympics.
A.regarded
B.was regarded
C.has regarded
D.had been regarded
探测器上的三位置开关可由左或右拨动,这取决于使用哪种()。
A.操作状态
B.操作方式
C.操作程序
D.操作需要