The player needs to serve the zones across the top first line (6 serves) and then switch ends and serve the next 6 serves from line 2. Repeat for the 3rd and 4th line. Keep a score of the zones hit with the 24 serves. You can toughen the drill by putting an elastic across the net and have them serve the deep zones under the elastic
SHORT ZONES (Short-Zones PDF)
DEEP ZONES (Deep-Zones PDF)
DEEP CORNER ZONES (Deep-Corner-Zones PDF)
MIX OF ALL SIX ZONES (Mix-of-All-Six-Zones PDF)

cant open up pdf
This has been fixed. You should be able to open them now. Enjoy!