Translation

• a thousand miles
• a thousand li (i.e. 500 kilometers)
• a long distance

Examples

• 电脑产业的发展一日千里。
  The development of the computer industry has been very rapid.
• 失之毫厘，谬之千里。
  Slight inattention can cause a great disaster.
• 在中国，人们常把有能力的人喻为“千里马”。
  In China, talented people are often described as "ten thousand mile horses".
• 有缘千里来相会，无缘对面不相逢。
  Those fated to meet will do so regardless of distance. Those not fated will not, even if they are across from one another.