only of metal, which wears away by friction.
而是由金属组成，而金属可以随着磨擦而磨损殆尽。
新概念英语第四册 Lesson 37 The process of ageing

📚 句中词汇解析

从本句中提取的重要词汇

away [ə'we] 词频1
adv. 离开，远离;在远处;消失; adj. 不在的;遥远的;客场比赛;
💡 a(on)+broad→在远方；离去；不在
"In the hotel, the old men were drinking away as usual."
在旅馆里, 这些老人和往常一样喝个不停.
近义：abroad, out, outdoors, outside, without
friction ['frɪkʃən] 词频4
n. 摩擦;冲突，不和;摩擦力;
💡 frica, frict 表”摩擦”
"the coefficient of friction"
摩擦系数
近义：massage, rub, scour, scrub, swab, swob
metal ['mɛtl] 词频1
n. 金属;金属元素;成色;金色; vt. 以金属覆盖;
💡 我的(me)十个(t)尖棍(al)是 金属做的
"the expansion and contraction of the metal"
金属的膨胀与收缩
近义：brass, sheeting
wears
v. 穿着( wear的第三人称单数 ); 磨成; 使疲乏; 同意

📚 更多「新概念英语第四册」例句

Because they destroy so many insects, and insects include some of the greatest enemies of the human race.
因为它们能消灭那么多的昆虫，其中包括一些人类的大敌，
or even, of there nough, in other departments of the same firm.
甚至往往不能与本公司的其他部门的同行们。
The turtle at last gives up by pulling his feet under his shell and the game is over.
海龟终于屈服了，将4条腿缩进壳内。
He must strive continually to think of, and use, form in its full spatial completeness.
他必须勤于想像并且利用形体在空间中的完整性。
A man without an education, many of us believe,
我们许多人都相信，一个没有受过教育的人，
But a watch could never repair itself----it does not consist of living parts,
但是，手表决不会自行修理，它不是由有生命的部件组成，