记忆方法
双解例句
小知识
A period is all about defining when something begins and ends. Class periods usually last about forty-five minutes. Following the last food fight, there was a period of relative peace in the school.
You know that dot at the end of a sentence? That's a period too. It means the sentence is over. In sports, games are often divided into playing periods: an ice hockey game, for example, has three periods. If you're a dinosaur buff, you know that this word can also refer to expanses of geologic time. The stegosaurus lived during the Jurassic period, for example, while the Tyrannosaurus rex and triceratops lived during the Cretaceous period.
实用短语
常用短语
单词用法
long period长期的;长周期
short period adj.短周期的;短过期的
transition period过渡时期
age:常指具有显著特征或以某杰出人物命名的历史时代或时期。
epoch:正式用词,侧重指以某重大事件或巨大变化为起点的新的历史时期。
era:书面语用词,指历史上的纪元、年代,可与epoch和age互换,侧重时期的延续性和整个历程。
period:最普通用词,概念广泛,时间长短不限,既可指任何一个历史时期,又可指个人或自然界的一个发展阶段。
times:侧重某一特定时期。
词根词缀
词根: od
1. =way,表示”路,走”; 2. 表示”电极”
adj.
periodic 周期的, 定期的period周期+ic……的→adj.周期的, 定期的
n.
anode [电]阳极, 正极an上+ode电极→n.[电]阳极, 正极
cathode [电]阴极,负极cath下+ode电极→n. [电]阴极,负极
diode 二极管di两个+ode电极→两个电极→二极管
method 方法,办法meth=meta+od路,走→n.方法,办法
period 时期, 学时,周期peri周围+od路,走→走一周
periodical 期刊,杂志periodic周期的+al物→n. 期刊,杂志
同义词辨析
同义词
同根词
词根:period
adj.periodical[数] 周期的;定期的
periodic周期的;定期的
adv.periodically定期地;周期性地;偶尔;间歇
n.periodical期刊;杂志
periodicity[数] 周期性;频率;定期性