After strong progress from 2007 to 2009 , this year saw some slippage , mr. zhang said at a news conference .
张先生在一次新闻发布会上表示,继2007年至2009年强劲的发展之后,该计划今年出现了一些延误。
Slippage shipment is one of the shipment technologies of large structure including platform jackets and platform blocks , by which the classic construction method is replaced for greatly decreasing the cost .