Icalledyou10:30p.m,butyoudidn'tanswerit.Imyworkandabath.()A.wasdoing;hadtakenB.haddone;hadtakenC.wasdoing;wastakenD.haddone;wastaking
I called you 10:30 p.m,but you didn't answer it.
I _____my work and ______a bath.( )
A. was doing; had taken
B. had done; had taken
C. was doing; was taken
D. had done; was taking
首先"我"与"洗澡"之间是主动关系,故C选项直接排除;根据句意可知应该是先完成工作,然后才洗澡,故前一横线处使用过去完成时(洗澡发生在过去,过去的过去即过去完成时),因此A选项排除;答句的句意是"你打电话来的时候我做完了工作,正在洗澡",故后一横线处需使用过去进行时,因此B选项排除.综上,本题答案为D选项.
无穷级数求极限问题求极限n→∞时lim∑1/{n+[(i^2+1)/n]},i从1到n的值这题目用的 2020-03-31 …
.定义:设有限集合A={x|x=ai,i≤n,i∈N+,n∈N+},S=a1+a2+…+an,则S 2020-04-25 …
向量空间证明题怎么证明?设α1,α2...,αn和β1,β2,...βn是n维列向量空间R^n的两 2020-05-13 …
1.已知数列{a(n)}满足a(n)a(n+1)a(n+2)a(n+3)=24,且a1=1a2=2 2020-07-09 …
P=A(1+i)^-1+A(1+i)^-2+A(i+i)^-3+……A(1+i)^-n(1)将两边 2020-07-25 …
已知一个边长为a的等边三角形,现将其边长n(n为大于2的整数)等分,并以相邻等分点为顶点向外作小等 2020-08-01 …
高次复数方程1.为什么方程i^3=1的解是1,(√3i-1)/2和(-√3i-1)/2.2.解复数 2020-08-02 …
求证e^i(4π/n)+e^i(8π/n)+...+e^i4(n-1)π/n+e^i(4nπ/n)= 2020-11-01 …
一道高数求极限问题lim(Σ(i/(n2+n+i))n趋向无穷大n2表示n平方,Σ是i从1加到n,谢 2020-11-30 …
在资金时间价值计算时,i和n给定,下列等式中正确的有().A.(F/A,i,n)=[(P/F,i,n 2021-01-14 …