1. The seabed has presented a fetile hunting ground for marine archaeologists. On land, ancient artifacts may crumble, but in the sea .......... protect thousands of years old treasures.

2. Since the invention of surveying instruments such as magnetometers, revelations of .......... in the seabed can be found by divers.

3. Sonar was used to find remnants of Cleaopatra's palace, ancient statues and the treasures hidden under layers of silt. Marine archaeologist Frank Goddio created .......... maps to reveal what lay under the sediment.

4. As underwater exploration continued, Robert Ballard, marine scientist realized scuba divers and submersibles were limited in how far they could descend. His name has become .......... with pioneering the use of remote controlled vehicles for exploration.

5. Remote controlled vehicles allowed exploration at depths of 2500 ft in the Mediterranean. An ROV sent down to that depth used a robotic arm to retrieve 150 .......... containing wine, olive oil and fish sauce.

6. The use of a tethered remote controlled vehicle discovered sunken Mediterranean trading ships and changed historian's opinion of ancient sailors venturing close to shore. New evidence disclosed these sailors could .......... across the sea.

7. Investigation into the wreck of the Titanic showed it did not have a huge gash caused by an iceberg. Rather the ship went down because of thin openings over the watertight holds, critical to it's .......... .

8. The use of remote vehicles has allowed the user to precisely .......... into dangerous areas beyond the capabilityof a diver.

9. The design of a slowly moving propeller prevents sand from being blown up from the seabed, which might have .......... the controller's view.

10. As scuba divers can safely venture no deeper than 200 feet, the invention of remote vehicles was responsible for finding remarkably well preserved artifacts as well as .......... many theories about the cause of disasters.