Explorer Robert Ballard searched the sunken ship---the Titanic for more than 20 years and also, with his cameras, he _____ the hole along the side of the ship which had caused it to fill with water and sink.

—I’m sure Andrew will win the first prize in the final.—I think so. He ________ for it for months.

Large quantities of money_____ to the poor in that area. .

Seeing the chemical ________ to the sunlight, Mr. Lee warned the workers to be careful when dealing with it.

The leaders from some of the countries suggested the nuclear weapon about Iran worth paying attention _______ at the international conference.