The city of Chengdu has grown so fast that it's at least ______ what it used to be．

A．five times the size of

B．five times the size as large as

C．five times larger

D．five limes size as

如果工程项目进度计划制定得既可行又优化，则可以使工期缩短，且可能获得较好的质量和较低的费用，这表明，工程项目投资、进度、质量三大目标之间存在( )的关系。

A．对立

B．统一

C．既对立又统一

D．既不对立又不统一