The phrase "achieve this difficult" is not correct in English.
It seems to be an incomplete expression and lacks clarity.
Example: "It is challenging to achieve this difficult task within the given timeframe."
Alternatives: "accomplish this challenging" or "attain this tough".
As a rule family members probably should avoid editor-writer collaborations — the writer-editor relationship is fraught enough as it is — but the son did some fairly hands-on editing to help achieve this difficult birth.
Increased collaboration with locals appears to be the most supported strategy to achieve this difficult goal.
Nature has, however, evolved efficient pathways to achieve this difficult transformation.
To achieve this difficult but important task, this paper introduces a new procedure of the genetic algorithm hybridized with the least squares method to estimate the model.
"I want to thank the president of the FAF, Mohamed Raouraoua, with whom I have worked for three years to realise our objectives and who put at my disposal a squad with all the necessary means to achieve this difficult mission.
Our ability to achieve this difficult separation stems from the presence of optically pure l-aspartyl side chains in the ligand.
Hardly anyone achieves this difficult dream.
They have achieved this difficult task not by selecting Adil Rashid in their Test squad for Cardiff, but by creating the possibility that they might leave him out of their final XI next Wednesday morning.
Thus far, no scheme has achieved this difficult goal.
The procedure to achieve this is difficult, and would likely take an entire sitting day.
In achieving this extraordinarily difficult compromise, Wren had not just tested his genius to the limits, but realised the most monumentally discreet of all English compromises.
