【简答题】已知集合A={a 1 ,a 2 ,…,a k (k≥2)},其中a i ∈Z(i=1,2,…,k),由A中的元素构成两个相应的集合:S={(a,b)|a∈A,b∈A,a+b∈A},T={(a,b)|a∈A,b∈A,a-b∈A},其中(a,b)是有序数对,集合S和T中的元素个数分别为m和n,若对于任意的a∈A,总有-a A,则称集合A具有性质P。 (1)检验集合{0,1,2,3}与{-1,2,3}是...
【多选题】黄芪鉴别特征为
C.
切片镜检,近栓内层有时可见石细胞及管状木栓组织
【简答题】Translate the following sentences into Chinese.英译汉 1. Prfessor Smith's lecture on body language was so important that all of the students took it seriously. 2. Realizing it wasn't her fault, the chai...
【单选题】某公司获得银行贷款100万元,年利率为6%,期限为三年,按年计息,单利计算,则到期后应偿还银行本息共为
【单选题】对于两个集合s1和s2,s1 < s2 是 指
【简答题】Realizing it wasn't her fault, the chairman smiled at her to lighten the atmosphere.