As a reasonable guess, they might, on an average, be 100 light years away.
據合理推算，外星人離我們平均距離也有100光年之遠
新概念英語第四冊
Lesson 43 Are there strangers in space
?? 句中詞匯解析
從本句中提取的重要詞匯
adj. 合理的，公道的;明白道理的;適當的;有理性的;
?? reason合理+able形容詞后綴, 具有某種性質的 → 合理的, 通情達理的
"There is reasonable concordance between the two sets of results."
兩組結果之間有著合理的一致。
近義：intelligent, levelheaded, logic, logical, moderate, modest
反義：illogical, inane, inconsistent, irrational, mad, meaningless
adv. 離開，遠離;在遠處;消失;
adj. 不在的;遙遠的;客場比賽;
?? a(on)+broad→在遠方；離去；不在
"In the hotel, the old men were drinking away as usual."
在旅館里, 這些老人和往常一樣喝個不停.
近義：abroad, out, outdoors, outside, without
vt. 推測;猜測，臆測;猜中;假定，認為;
vi. 猜，猜測;猜對;
n. 猜測;推斷;
?? 聯想：猜也猜不著“該死
"You'll never guess what's happened!"
你根本猜不到出了什么事！
近義：presume, sense, assume, suspect, speculate, suppose
反義：learn, miscalculate, misdeem, miss, confuse, fail
adj. 平常的;平均的;典型的;（價值、比率等的）平均數的;
n. 平均水平;（速度等的）平均率;平均估價;
vt. [數學] 計算…的平均值;調和，拉平;分攤;按比例（或平均）分配（利潤等）;
vi. 平均：作為或達到一個中間值;維持（有利的）平均價格;
?? aver(every每個)+age(后綴):- 平均的
"a rise in average earnings"
平均收入的增加
近義：curve, mean, median, medium, middle, midpoint
反義：appreciable, memorable, notable, noted, noticeable, notorious
n. 光;發光體;電燈;點火器;
adj. 輕的;明亮的;淺色的;少量的;
v. 點燃;照亮;用光指引;
adv. 輕地，輕裝地;
?? 房間光線（light）明暗度正好（right）
"The office was light and airy."
辦公室又明亮又通風。
近義：illuminate, illumine, lighten, brighten, ignite, incandescence
反義：quench, douse, extinguish, murk, murkiness, obscurity