快速,迅速
fast
  We set off at a good clip, but we gradually slowed down. 我们出发时速度很快,可是后来渐渐慢了下来。 
 Government investment in research has been increasing at a fast clip.
 The action proceeds at a fast clip, with all the main characters introduced in the first five minutes.
 Even the commuter trains move at a good clip.
 The cattle headed up the hill at a good clip.
 See also: clip noun (SPEED)