ear前面用an
The radio telescope is like an ear， listening to tell meaningful radio messages from white noise in the universe.
电波望远镜就像一只耳朵，从宇宙的白噪音中分辨出有意义的无线电信息。
The little boy has a hearing defect in his right ear.
这个小男孩的右耳听力有缺陷。
ear前面加an。ear用作单数时，前面都加an，因为ear是元音字母开头，有耳耳朵有…耳朵的耳朵…的灵敏的听力辨音力的意思。
