What should you do to verify the meaning of a difficult word? look up the word in an index
look up the definition in a dictionary
find a synonym for the word in a thesarus
use the word in a new sentence

she was killed in her home during hurricane katrina. b.she was relocated to another town after hurricane katrina. c.she died trying to get victims of the hurricane to safety. d.she is still missing — police do not know where she is.

the following key ideas correctly express the key sentence.

restate key idea: most people can learn to swim in ten short lessons.

restate key idea: the majority of water-accident victims require mouth-to-mouth breathing.

restate key idea: an empty, tightly closed gallon jug will support a tired swimmer.  

restate key idea: first aid is to prevent accidents as well as assist in rescue.

explanation: the key idea needs to have the same topic as the key sentence (drowning and safety).