What kind of tool did the experimenters watch while the rats ran? Click to view the passage "Rat Race."
A. A scale
B. A ruler
C. A maze
D. A stopwatch
SUBMIT

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).

fond of fighting is the answer