Understanding cultural habits of another nation is difficult thing.
I really appreciate _____ to relax with you on this nice island.
The bell _____ the end of the class rang, _____ our heated discussion.
As early as 1647 Ohio made a decision that free, tax supported schools must be established in every town _____ 50 households or more.
Although punctual himself, the professor was quite used _____ late for his lecture.
The pressure _____ causes Americans to be energetic, but it also puts them under a constant emotional strain (过度紧张).