早教吧作业答案频道 -->英语-->
TheRussianrocketdesignerhasdied.Formanyyears,he______asanimportantassistanttothefatherofSovietspaceprogram.A.servesB.wasservingC.servedD.hasserved为什么选C
题目详情
The Russian rocket designer has died. For many years, he ______ as an important assistant to
the father of Soviet space program.
A. serves
B. was serving
C. served
D. has served
为什么选C
the father of Soviet space program.
A. serves
B. was serving
C. served
D. has served
为什么选C
▼优质解答
答案和解析
C
死前,他一直以一种助手身份服务,工作.过去时
死前,他一直以一种助手身份服务,工作.过去时
看了 TheRussianrock...的网友还看了以下:
动能公式只与初速度和末速度有关吗?将物体以初速度v0斜向上抛出,v0与水平方向的夹角为θ,落地时物体 2020-03-30 …
已知:2Zn(s)+O2(g)=2ZnO(s)△H=-701.0kJ/mol2Hg(l)+O2(g 2020-04-07 …
已知:(1)2Fe(s)+O2(g)=2FeO(s)△H=-544kJ·mol-1(2)2Al(s 2020-04-07 …
1mol氢气与1/2mol氧气反应生成1mol水蒸气△H为a,生成1mol液态水△H为b,那么a, 2020-05-17 …
已知热化学反应方程式:Zn(s)+1/2O2(g)=ZnO(s)△H=-351.5kJ/mol;H 2020-07-09 …
已知反应H2(g)+Cl2(g)=2HCl(g)ΔH=-184.6kJ/mol,则反应:HCl(g 2020-07-18 …
已知H2(g)+Cl2(g)=2HCl(g)△H=―184.6kJ·mol-1,则HCl(g)=1 2020-07-18 …
已知1/2H2(g)+1/2C12(g)═HCl(g);△H=﹣92.3kJ•mol﹣1,则反应2 2020-07-18 …
已知:2Zn(s)+O2(g)2ZnO(s)ΔH=-701.0kJ·mol-12Hg(l)+O2( 2020-07-19 …
已知:Fe2O3(s)+3C(石墨)=2Fe(s)+3CO(g)ΔH=+489.0kJ·mol-1 2020-07-19 …