【单选题】(2018· 云南中考 ) 按一定规律排列的单项式: a ,- a 2 , a 3 ,- a 4 , a 5 ,- a 6 ,...,第 n 个单项式是 ( )
【单选题】桑蚕丝在显微镜下观察到的横截面形状是什么样的?
【简答题】Search for all the affixes practiced in “WORD BUILDING ”exercises in each unit of BOOK I , II, III, and IV , and in a very efficient way,collect them,arrange them ,list them with citations ,generali...
【单选题】桑蚕丝在显微镜下观察到的横截面形状是什么样的?
【单选题】(2019 云南 ) 按一定规律排列的单项式: x 3 ,- x 5 , x 7 ,- x 9 , x 11 , ... ,第 n 个单项式是 ( )
A.
( - 1) n - 1 x 2 n - 1
C.
( - 1) n - 1 x 2 n + 1
【单选题】(2019・云南中考)按一定规律排列的单项式:x 3 ,-x 5 ,x 7 ,-x 9 ,x 11 ......第n个单项式是( )