Complex sentence: Air units may Counterair (attack enemy air at their bases-British air factors in Malta may decline combat but must be inverted if they do so), give Ground Support to attackers (including exploiting armour) or Defensive Air Support.
Split into simpler sentences: Air units may Counterair (attacking enemy air at their bases-British air factors in Malta may decline combat but must be inverted if they do so). They may also give Ground Support to attackers (including exploiting armour) or Defensive Air Support.