51.   The Latin American push, comes as Delta faces a stiff challenge in Asia.

52.   The NHL faces some stiff economic challenges.

53.   The seven Republican senators facing stiff challenges have been stuck in Washington, unable to campaign much during the week because the Senate has been in session.

54.   The rejuvenated East Lake will provide an incredibly stiff challenge this week to the best golfers on the tour.

55.   The trails are not a stiff challenge to truly advanced skiers, but the cruising is ultrafine on most days, with still good snowmaking and grooming.

56.   There are already signs that Rogers Cantel faces a stiff challenge dealing with heightened competition.

57.   These changes have opened vast new opportunities, but they also present stiff challenges.

58.   Though it faces a stiff challenge, the merger proposal is moving smoothly toward a vote.

59.   Trying to build in a historic district is a stiff challenge, Ms. Hoffman said.

60.   Until he answers a stiff challenge, a question will remain unanswered.