You 16 the mirror to find a tiny red spot on the base of your lower lashes.
答案：(A) check out
【句型】check out 固定片語「查看」，表示「你去照鏡子查看，發現一個小紅點」；look into（調查，不太合「照鏡子查看外觀」的動作）、watch over（看守）、see through（看穿）都不合。
check out 你最熟的一定是「結帳、退房」——超市的 checkout 櫃台、飯店退房叫 check out。所以看到 You {16} the mirror 這個空格，你反而覺得 check out 不對，轉去挑看起來比較「正經」的 look into（調查）。但 check out 還有一個很常用的意思：「看一看、查看」（牛津高階詞典 Oxford Advanced Learner's Dictionary 把這個用法列為 to look at or examine，標示為口語）。
把句子還原成完整的動作順序：You check out the mirror to find a tiny red spot on the base of your lower lashes.——你去照鏡子看一看，結果發現下睫毛根部有個小紅點。後面的 to find 是表示結果的不定詞（去看，結果發現），所以前面必須是「用眼睛看」這個動作，不是「調查」。這一題的鑑別度偏低，代表連高分群考生也常挑 look into，問題出在中文：「查看」和「調查」在中文裡很接近，但英文分工很清楚——look into 用在案件、問題、抱怨，不會用在「照鏡子」這種單純用眼睛看的動作。
look into（調查、深入了解）後面接的是需要查明的事，像 look into the accident（調查這起事故）。watch over（看顧、守護）是照看人或東西，像 watch over the children（看顧孩子）。see through（看穿）是識破謊言或詭計，像 see through his lies（看穿他的謊言）。這裡可以順便把國中學過的一組 look 複習一次：look at（看）、look for（尋找）、look after（照顧）——同一個動詞換一個介系詞或介副詞，意思就整組換掉，check 這一家也一樣。
check out（查看、看一看）、check out of a hotel（辦理退房）、check in（辦理報到、登記入住）、look into（調查）、look after（照顧）、look for（尋找）、watch over（看顧、守護）、see through（看穿）。
You begin to notice a bit of pain on your eyelid each time you blink. You 16 the mirror to find a tiny red spot on the base of your lower lashes. These 17 are probably the beginning of an eye stye. An eye stye is a small bump, resembling a pimple, that develops when an oil gland at the edge of an eyelid becomes infected by bacteria. These bacteria are found in the nose and are easily 18 to the eye when you rub your nose, then your eye. Pus will build up in the center of the stye, causing a yellowish spot. Usually a stye is accompanied by a swollen eye.
19 a stye can look unpleasant at times, it is usually harmless and doesn't cause vision problems. Most styes heal on their own within a few days. You might speed up healing time by gently pressing a warm washcloth 20 your eyelid for 10 minutes, 3 or 4 times a day. Make sure you don't squeeze or pop a stye like you would a pimple. Doing so may cause a severe eye infection.