◎ 题干
We succeeded,after a good deal of _      ,in inventing the machine.        
[     ]
A.  trial and error                  
B.  morning and night        
C.  bittemess and hard              
D.  failure and success
◎ 答案
查看答案
◎ 解析
查看解析
◎ 知识点
    根据n多题专家分析,试题“We succeeded,after a good deal of _,in inventing the machine.[ ]A.trial and errorB.morning and nightC.bittemess and hardD.failure and success…”主要考查了你对  【名词】  等知识点的理解和应用能力。关于这些知识点的“档案”,你可以点击相应的链接进行查看和学习。