流体在管道中作稳定流动时，同一时间内流过管道每一截面的质量相等。

Only when he met the girl his aunt introduced to him ____ that he had seen her before.   [    ]

A. he realized    

B. he did realize  

C. realized he      

D. did he realize

餐饮营销宏观环境

人民法院受理破产案件后，债务人对债权人的个别清偿行为应如何处理()

A．一律认定无效

B．均可由其他债权人撤销

C．无效，但是债务人正常生产经营所必需的除外

D．可由其他债权人撤销，但是债务人正常生产经营所必需的除外

He went to the library ______ last night, but you broke your word.

A．no doubt

B．in need

C．on earth

D．in truth

等差数列a_n)中，已知a₂+a₅=4，a_n=33，则n为（）。

A.48

B.49

C.50

D.51