That will be hard to sustain, given America's fiscal woes.The second constraint is public opinion.
But that is a hard point to sustain, given that the past few years have seen a worldwide recession and modest recovery.
This strategy will be somewhat difficult to sustain given that Andersen used to take pride in the degree of integration across the firm.
It's vital to see that support for such work is sustained, given the early stages of understanding and enormous significance of these trends.
In her speech to the Tory conference, May appeared to be leaning to the leave side though ministers believe that would be a difficult position to sustain given her support for EU criminal justice cooperation.
Indeed, a boom would be difficult to sustain, given China's slowdown, higher investment in energy-saving technologies, less emphasis on capital- and resource-oriented growth models around the world, and the delayed increase in supply that high prices induced.
"The principle of the licence fee in its current form is becoming harder and harder to sustain given changes in communications and media technology and services, and changing audience needs and behaviours.
Cinema owners have good reason to assume this robust increase will be sustained, given that the fourth quarter of the year includes Spectre, Star Wars: The Force Awakens and the final Hunger Games movie.
But aid workers in Laos query how long such a policy can be sustained, given that alternative crops often provide miserly returns from uncertain markets, not least because of Laos's appalling infrastructure.
"The issue going forward will be whether that confidence is sustained, given the troubled financial backdrop, and the apparent sputtering in consumer income growth," he wrote in a research note.
