Whether they wielded rods or pea shooters, knockers-up became 18 throughout the United Kingdom.
答案：(A) familiar presences
語意「敲窗人成為英國各地『熟悉的身影』」，familiar presences 符合，呼應後文描述他們每天早上出現在大街小巷；distant memories（遙遠的記憶，這裡是講他們當時「存在」不是「回憶」）、vague images（模糊的形象）、public eyesores（公眾眼中釘，語意相反）都不合。
presence 你背的多半是「出席、在場」這個抽象意思（Your presence is required. 需要您親自出席），而且是不可數的。但 presence 也可以當可數名詞，指存在感明顯的人物、身影，familiar presences 就是「熟悉的身影」。看到它後面加了 -s，就該想到這裡用的是可數的那個意思。
看時態和後文。本句 knockers-up became ___ throughout the United Kingdom 用的是 became，講的是他們當年在各地成為什麼。下一句 Every morning, these people... were seen in big streets and small alleys（每天早上，這些人出現在大街小巷）——were seen（被看見）正是「熟悉的身影」的具體描述。
distant memories（遙遠的記憶）是後人回頭看的角度，但本段講的是他們當年還在工作的時期，時間點不對；vague images（模糊的形象）與「每天早上都看得到」矛盾；public eyesores（有礙觀瞻的東西）帶明顯貶意，但全文對敲窗人是正面描述，最後一句還說鬧鐘取代不了那份人情味。
a familiar presence（熟悉的身影）、in the presence of（在……面前）、presence of mind（沉著、鎮定）、become a common sight（成為常見的景象）、a distant memory（遙遠的記憶）、an eyesore（有礙觀瞻的東西）。
The modern worker rolls out of bed, groans, and turns off an alarm clock before reluctantly getting up for the day’s work. But how did people get to work on time before alarm clocks were widely used? During the second Industrial Age, people toiled at unusual hours in mines or factories and often had to get up for work early in the morning. They 16 alarm clocks because adjustable alarms had been invented by the mid-19th century. But the new device was still relatively expensive and unreliable. British workers thus relied on a human alarm clock known as a “knocker-up.”
17 sticks or pea shooters, the human alarms would tour the streets, tap on windows, or blast them with dried peas, trying to wake paying customers in time for work. Whether they wielded rods or pea shooters, knockers-up became 18 throughout the United Kingdom. Every morning, these people, often older in age, were seen in big streets and small alleys, waking up their customers professionally. They usually would not leave people’s houses until they were sure their customers were awake.
While the practice continued in some parts of the country until the 1970s, it 19 as alarm clocks became more widespread and affordable. Today, beeping alarm clocks and smartphones that play morning music are surely simpler and more convenient. However, they cannot 20 the personal attention coming from the distinctive tap of a pea shooter.