There were certainly things I was scared to do, but I never thought I wasn't up for the challenge.
Rooney MaraClimate change is the Everest of all problems, the thorniest challenge facing humankind.
Lewis Gordon PughThere were different challenges along the way. Certainly the food shortage was unpleasant.
Leroy ChiaoThe successful business executive can handle challenges and solve problems at a remarkable clip.
Zig ZiglarIt's a real challenge to complete a story arc and end up with a cool punchline in 120 characters.
Mark Hoppus