三、閱讀測驗：(每題 2 分，共 10 分) 【A】 There are usually 31,557,600 seconds in one year. Last yearwas one second longer, though. Why? We added a leap second. Earth is slowing down. That makes each day longer. So, weneed to add some time to our clocks. Then, our clocks’ time canbe the same as the Earth’s time. If we don’t, noon will happenat one o’clock one day.   Most people shouldn’t worry about leap seconds. Many clocksadd them for you. However, they can cause trouble. A leap secondin 2015 took down many Web sites.
【題組】31. Why did we need to add a leap second in 2016?
(A) Because our Earth is slowing down.
(B) Because 2015 was one second longer.
(C) Because we lost a second each day last year.
(D) Because noon could happen at one o’clock.