difficult to combine difficult to come difficult to come up difficult to comment difficult to communicate difficult to compare difficult to compete difficult to complete difficult to completely difficult to comprehend difficult to conceal difficult to conceive difficult to concentrate difficult to conduct difficult to connect difficult to contact difficult to contain difficult to control difficult to convey difficult to convince difficult to coordinate difficult to cope difficult to correct difficult to count difficult to counterfeit difficult to cover difficult to crack difficult to create difficult to cross difficult to cultivate difficult to cure difficult to cut difficult to date difficult to deal difficult to decide difficult to decipher difficult to defeat difficult to defend difficult to define difficult to deliver difficult to demonstrate difficult to describe difficult to design difficult to destroy difficult to detect difficult to determine difficult to determine how difficult to develop difficult to diagnose difficult to differentiate difficult to digest difficult to discern difficult to discover difficult to discuss difficult to distinguish difficult to do difficult to do so difficult to draw difficult to drive difficult to eat difficult to eliminate difficult to endure difficult to enforce difficult to enjoy difficult to ensure difficult to enter difficult to eradicate difficult to escape difficult to establish difficult to estimate difficult to evaluate difficult to explain difficult to exploit difficult to express difficult to extract difficult to face difficult to fall difficult to fathom difficult to feed difficult to feel difficult to fight difficult to figure difficult to figure out difficult to fill difficult to finance difficult to find difficult to find a good difficult to find a job difficult to find out difficult to find someone difficult to find the right difficult to finish difficult to fit difficult to fix difficult to fly difficult to focus difficult to follow difficult to forecast difficult to forge