The standard electrocardiogram shows the heart's electrical activity from different angles through "leads.". How many leads are recorded?

Normally, the number of cycles of sleep stages that occur per night is ____ cycles

a. 4 to 6 c. 8 to 10 b. 6 to 8 d. 10 to 12

Another term for cloudiness is ____________________

Fill in the blank(s) with correct word