Which of these sentences is an example of a compound sentence? a. The athletes trained for months before they c. Seventh and eighth graders are preparing
competed in the event last week.
for their final exams.
b. Kelvin spent the entire summer working at d. The chicken satay was very flavorful, but the
summer camp
curry was so fragrant and warming.

d. The chicken satay was very flavorful, but the

summer camp

curry was so fragrant and warming.

Explanation:

compound sentences must contain a conjunction and in this case, "but" is the conjuction.

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).