The China Conservation and Research Center for the Giant Panda (CCRCGP) is located in the Wolong Nature Reserve. For over 20 years the organization has worked for the preservation of the panda population and has now resolved three key problems of breeding which restricted reproduction of the panda for a long time.
Plug-ins were invented to work around the limitations of early HTML and deliver more interactive content. A plug-in is an additional piece of software that specializes in processing particular types of content. For example, users may download and install a plug-in like Adobe Flash Player to view a web page which contains a video or an interactive game.
A fillet weld all around a hole is not a plug weld... it is a fillet weld. A plug weld is a weld in a hole that is filled to some depth. Per AWS A2.4:2012 9.1.4: The plug weld symbol shall not be used to designate fillet welds in holes.