has been basing

• present perfect progressive

  present perfect progressive

  Used to describe an action that began in the past, has continued continuously, and is still in progress.

  of base (3rd person singular).
  base

  noun

  the bottom support of anything; that on which a thing stands or rests.

Related Words

• camp
• center
• depot
• field
• garrison
• home
• port
• post
• settlement
• site
• station
• terminal