This depends on the precise radio frequency of the 21-cm wavelength, or 1420 megacycles per second.
這種通訊聯系要靠21厘米波段,即每秒1420兆周的精確無線電頻率。
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

precise [pr?'sa?s] 詞頻4 詞根: pre
adj. 清晰的;精確的;正規的;精密;
?? pre….前的,預先+cise切→預先切好的→精確的
"At that precise moment, Miss Pulteney came into the office."
就在那時, 普爾特尼小姐走進了辦公室.
近義:pinpoint, accurate, correct, crisp, exact, pernickety 反義:indefinite, lax, loose, mistakable, sketchy, uncertain
radio ['red?o] 詞頻2 詞根: radi
n. 無線電;收音機;無線電廣播臺;無線電收發報機; vt.& vi. 用無線電發送訊息;作無線電廣播;用X射線拍照;
?? radi 表”射線,輻射,廣播”
"The President gave an address to the nation over the radio."
總統向全國發表廣播演說.
近義:transmit, radiophonics, radiotelephony
frequency ['frikw?nsi] 詞頻5 詞根: frequen
n. 頻繁性;[數][物]頻率,次數;頻率分布;
?? fr + equ =equal,even,表示“相等,平均” + enc + y [形容詞后綴] → n.屢次;次數;頻率
"Fatal road accidents have decreased in frequency over recent years."
近年來致命交通事故發生率已經下降。
近義:assiduity, periodicity, regularity, chronicity 反義:uncommonness
wavelength ['wevl??θ]
n. <物>波長;波段;完全一致,融洽;
?? wave波+length長度 → 波長
"Radio One has broadcast on this wavelength for years."
廣播1臺已經用這個波長廣播多年了.
近義:w.l.
second ['s?k?nd] 詞頻1 詞根: 跟隨
n. 秒;瞬間;次貨;第二份食物; adj. 第二的;次要的;居第二位的;另外的; adv. 第二;其次;以第二位; vt. 支持;臨時調派;附議;贊成提案;
?? sec跟隨+ond=one第一→跟隨第一個之后→第二;秒
"She was in the second year of her apprenticeship as a carpenter."
她當木工學徒已是第二年了。
近義:back, backstop, reinforce, support, advocate, endorse 反義:oppose, confront, contradict, counter, fence

?? 更多「新概念英語第四冊」例句