Erection of the penis is caused by
A) erectile tissues that become engorged with blood.
B) the penis filling with the semen to be ejaculated.
C) contraction of the longitudinal muscles.
D) protrusion of the os penis, the penis bone.
E) None of the answers are correct.
A) erectile tissues that become engorged with blood.
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Cattle are usually fed ____ to ____ times a day
Fill in the blank(s) with correct word
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