問(wèn)題補(bǔ)充：
單選題
The Internet celebrated its birthday on September 2nd, by which time 40 years _______ since the first successful transfer of data between two computersA.has passedB.had passedC.passedD.have passed
網(wǎng)友答案：
熱心網(wǎng)友 1樓
B解析考查時(shí)態(tài)，by which time引導(dǎo)定語(yǔ)從句，by+過(guò)去時(shí)間，謂語(yǔ)用過(guò)去完成時(shí)，句意是：互聯(lián)網(wǎng)在九月二日慶祝了自己的生日，到這個(gè)時(shí)間時(shí)間為止自從兩臺(tái)計(jì)算機(jī)之間的第一個(gè)成功的通過(guò)的數(shù)據(jù)傳輸已經(jīng)過(guò)去有40年了。選B。
