【简答题】I have a friend who never exercises unless she’s training for a marathon.A. 1111MicrosoftInternetExplorer402DocumentNotSpecified7.8 磅Normal0我有一个朋友从来不锻炼,除非她去进行马拉松训练。B. 1111MicrosoftInternetExplorer402D...
【简答题】小红和小丽对问题“若方程组 a 1 x+ b 1 y= c 1 a 2 x+ b 2 y= c 2 的解是 x=3 y=-4 ,求方程组 3 a 1 x+2 b 1 y=5 c 1 3 a 2 x+2 b x y=5 c 2 的解”提出各自的想法.小红说:“这个题目好象条件不够,不能求解”;小丽说:“能不能把第二个方程组的两个方程的两边都除以5,通过整体代换的方法来解决”.参考他们的讨论,你认为这...
【单选题】根据下列文章,请回答 16~20 题。 I have a friend who is a team leader of about 25 employees who are primarily women. She' s found a trick that works for her most of the time, but not always. Those staff who appear...
A.
We shall not be moved.
B.
Money means .
C.
Photos taking are pleasant.
D.
There are people who are so careless about dressing.
【简答题】已知等差数列{a n }为递增数列,满足 a 3 2 =5 a 1 +5 a 5 -25 ,在等比数列{b n }中,b 3 =a 2 +2,b 4 =a 3 +5,b 5 =a 4 +13. (Ⅰ)求数列{b n }的通项公式b n ; (Ⅱ)若数列{b n }的前n项和为S n ,求证:数列{ S n + 5 4 }是等比数列.