Assertion: flask's opening | /r/HasProperty | difficult to access
Facets:
Source sentences:
text: In some situations, however, Schlenk bombs are less convenient than standard Schlenk flasks: they lack an accessible ground glass joint to attach additional apparatus; the opening provided by plug valves can be difficult to access with a spatula, and it can be much simpler to work with a septum designed to fit a ground glass joint than with a Teflon plug.