光速比音速快，所以有些人乍看之下很聪明，等到听到他们开口说话，愚笨的本性才表露无遗。

It is because light travels faster than sound that some people look brilliant before sounding stupid.

Source: Tatoeba

Sentence Composition

1 光速 guāngsù the speed of light
=2 比 Bǐ
  1. Belgium
  2. Belgian
  3. abbr. for 比利时 Bǐlìshí
=2 比 bī euphemistic variant of 屄 bī
=2 比 bǐ
  1. to compare
  2. (followed by a noun and adjective) more {adj.} than {noun}
  3. ratio
  4. to gesture
  5. (Taiwan pr. bì in some compounds derived from Classical Chinese)
=2 比 pí
  1. (obsolete on its own in Standard Chinese) used in 師比／师比 (shīpí, “ancient belt hook”)
  2. (obsolete on its own in Standard Chinese) used in 比蒲 (“placename”)
  3. (obsolete on its own in Standard Chinese) used in 皋比 (gāopí, “tiger skin”)
  4. used in 師比／师比 (shīpí, “ancient belt hook”)
  5. used in 比蒲 (“placename”)
  6. used in 皋比 (gāopí, “tiger skin”)
=2 比 bì
  1. (obsolete on its own in Standard Chinese) close; near
  2. (obsolete on its own in Standard Chinese) dense; closely packed
  3. close; near
  4. dense; closely packed
=2 比 pǐ
  1. (obsolete on its own in Standard Chinese) alternative form of 庀 (pǐ, “to have; to possess”)
  2. alternative form of 庀 (pǐ, “to have; to possess”)
3 音速 yīnsù speed of sound
4 快 kuài
  1. rapid
  2. quick
  3. speed
  4. rate
  5. soon
  6. almost
  7. to make haste
  8. clever
  9. sharp (of knives or wits)
  10. forthright
  11. plainspoken
  12. gratified
  13. pleased
  14. pleasant
5 所以 suǒyǐ
  1. therefore
  2. as a result
  3. so
  4. the reason why
6 有些人 yǒuxiērén some people
7 乍看 zhàkàn at first glance
8 之下 zhīxià
  1. under
  2. beneath
  3. less than
9 很 hěn
  1. very; quite
  2. (also, often used before an adjective without intensifying its meaning, i.e. as a meaningless syntactic element)
=10 聪明 cōngming
  1. intelligent; clever; bright
  2. acute (of sight and hearing)
=10 聪明 cōngmíng
  1. (archaic, of hearing and vision) sharp; keen; perceptive
  2. clever; intelligent; smart; bright
  3. sharp; keen; perceptive
11 等到 děngdào
  1. to wait until
  2. by the time when (sth is ready etc)
12 听到 tīngdào to hear
13 他们 tāmen they; them
14 开口 kāikǒu
  1. to open one's mouth
  2. to start to talk
15 说话 shuōhuà
  1. to speak
  2. to say
  3. to talk
  4. to gossip
  5. to tell stories
  6. talk
  7. word
16 愚笨 yúbèn
  1. stupid
  2. clumsy
=17 的 de
  1. of; ~'s (possessive particle)
  2. (used after an attribute when it modifies a noun)
  3. (used at the end of a declarative sentence for emphasis)
  4. (used after a noun, verb or adjective to form a nominal expression, as in 皮革的 pígéde "one made of leather" or 跑堂儿的 pǎotángrde "a waiter (literally, one who runs back and forth in a restaurant)" or 新的 xīnde "new one")
  5. also pr. dì or di in poetry and songs
=17 的 dī a taxi; a cab (abbr. for 的士 dīshì)
=17 的 dí really and truly
=17 的 dì (bound form) bull's-eye; target
18 本性 běnxìng
  1. natural instincts
  2. nature
  3. inherent quality
=19 才 cái
  1. ability; talent
  2. sb of a certain type
  3. a capable individual
  4. then and only then
  5. just now
  6. (before an expression of quantity) only
=19 才 cái
  1. (variant of 才 cái) just now
  2. (variant of 才 cái) (before an expression of quantity) only
20 表露无遗 biǎolùwúyí
  1. to show in full light
  2. to be revealed in its entirety