Dear teachers,

By supplying deficiencies of a quiz concerning the theme "Food Storage Containers" I found it difficult to use the term "ear", which I have to put in a gap of the following sentence.

"How many ears of corn should I get for dinner?"

I know something about "ear" as a vertebrate organ of hearing, as well as a small box in the upper corner of the page in a newspaper or periodical that contains a printed notice. I know even something about "ears" as headphones, or as a seed-bearing spike of a cereal plant such as corns. I remembered about "ear of oat" and "ear of rye", but in this case I was loss for an answer.

Would you be kind enough to explain to me in plain English the plausibility of the sentence above.Could you explain to me the meaning of the following sentence:

"Ears of corn were boiled or roasted over fire."

Thank you in advance for your efforts.