You only need to answer number 1 if u want pls

to create suspense.

a, b, and c are all correct.

two factors or characteristics of a chapter that might make it difficult to read would be words i don't understand, or if i don't fully understand what's going on in the chapter. strategies i can use to get through the difficult material would be a dictionary, and re-reading previous chapters to get a better grasp of what the author is trying to say.

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).