Though lacking money and support from his family, he ________ to complete the task by himself,

which brought him confidence and experience.[      ]

A. tried  

B. attempted

C. ran  

D. managed

塔吊的拆装必须由（）进行，拆装时应有技术和安全人员在现场监护。

A.建设行政主管部门颁发的拆装资质证书的专业队伍

B.项目

C.分包队

D.上级单位