【简答题】The number of passengers remained steady between 2004-200
【单选题】三相异步电动机电磁转矩的大小和( )成正比。
【单选题】已知一个等差数列的第5项等于10,前3项的和等于3,那么( )
【单选题】Steve Banks made personal contact with product users to discover what they wanted from his software.
【简答题】(本小题满分10分)已知等差数列{ a n }的首项 a 1 =1,公差 d >0,且第2项、第5项、第14项分别是一个等比数列的第二项、第三项、第四项. (Ⅰ)求数列{ a n }的通项公式; (Ⅱ)设 = ( n ∈N * ), = b 1 + b 2 +…+ b n ,是否存在最大的整数 t ,使得任意的 n 均有 总成立?若存在,求出 t ;若不存在,请说明理由
【单选题】Between 1950 and 2004, standards of living in the OECD countries
A.
did not change at all.
C.
all increased at the same rate.
D.
decreased at the same rate.
E.
decreased, but at different rates.
【单选题】已知数列{a n },{b n }都是公差为1的等差数列,其首项分别为a 1 ,b 1 且a 1 +b 1 =5,a 1 ,b 1 ∈N*,设c n = (n∈N*),则数列{c n }的前10项之和等于 [ ]
【单选题】已知等差数列的首项是 -10,公差是5,第10项是( )。
【单选题】Steve Banks made personal contact with product users to discover what they wanted from his software.