Sentence examples for so difficult to control from inspiring English sources

Why have the attacks been so difficult to control?

This article and the comments below perfectly illustrate why Health budgets are so difficult to control.

Practical implications are discussed with particular emphasis on why abnormal grain growth can be so difficult to control.

That's one of the reasons it was so difficult to control and got as large as it is.

Cauley, L. S. & Vella, A. T. Why is coinfection with influenza virus and bacteria so difficult to control?

It explains, too, why so many people try so hard to come and why immigration is so difficult to control.

I was simply reporting on a study that shows why it is so problematic and difficult to control.

He described Salaheddiin as a dense, heavily populated neighborhood with many entrances, so it was difficult to control.

The agricultural supply chain is highly fragmented, so it is difficult to control the quality of inputs.

UCG technology differs from conventional coal gasification in surface reactors, in that it is an invisible process, so it is difficult to control the reaction process and consistently produce hydrogen-rich syngas in the underground situation (Friedmann et al. 2009).

So it is usually difficult to control a complex network by adding the controllers to all nodes.