| The duly mapped portage trails were not a pathway out but a pathway in to a barely penetrable morass of fallen trees and boot-swallowing mud. |
| The outer membrane, as in a cell, is penetrable, filled with light, transparent, and attracting public view. |
| And who else but idiots would support a missile defence system that has proved penetrable and unworkable? |
| From alcohol they progress to opium, thence to heroin, allowing their language to get boozily baroque and even less penetrable. |
| Topical drug penetration, for example in the use of a cell penetrable peptide approach to enhance penetration of therapeutic compounds into skin. |
| The result can be criticism that is less penetrable than the work it addresses. |
