某井在井口憋压，油压开始上升缓慢，十多分钟后升到几个大气压后再也憋不起来，甚至下降，是说明深井泵工作状况？
参考答案：
此种现象说明深井泵凡尔或活塞漏失。
Mark wants to buy a particular painting. He makes his request known to an art dealer who sells him the painting, providing him with a certificate guaranteeing the authenticity of the painting. Several months later, Mark has the painting valued and he is informed that the painting is a fake.Required:Advise Mark whether he may take action against the art dealer to invalidate the contract of purchase of the painting. (10 marks)
有誓词称：“国民痛苦，水深火热；土匪军阀，为虎作伥；帝国主义，以枭以张。本军兴师，救国救民； * * 遗命，炳若晨星。”誓词所涉及的历史事件是（）
A、辛亥革命
B、北伐战争
C、抗日战争
D、解放战争
