沉默寡言

别看他平时总是沉默寡言不苟言笑，一旦遇到复杂技术难题却总能一针见血。

bié kàn tā píng shí zǒng shì chén mò guǎ yán bù gǒu yán xiào, yí dàn yù dào fù zá jì shù nán tí què zǒng néng yī zhēn jiàn xiě.

Although he is usually taciturn and reserved, he can always hit the nail on the head when encountering complex technical problems.

看到平时沉默寡言的他今天在台上侃侃而谈，大家都露出了诧异的神情。

kàn dào píng shí chén mò guǎ yán de tā jīn tiān zài tái shàng kǎn kǎn ér tán, dà jiā dōu lù chū le chà yì de shén qíng.

Everyone looked surprised when they saw him, who was usually taciturn, talking freely on stage today.

一谈起自己沉醉钻研了数十载的中国古代天文历法演进史，平日里沉默寡言的老先生顿时神采奕奕、滔滔不绝。

yī tán qǐ zì jǐ chén zuì zuān yán le shù shí zài de zhōng guó gǔ dài tiān wén lì fǎ yǎn jìn shǐ, píng rì lǐ chén mò guǎ yán de lǎo xiān shēng dùn shí shén cǎi yì yì, tāo tāo bù jué.

When he talked about the evolution of ancient Chinese astronomy and calendar, which he had been studying for decades, the usually taciturn old man suddenly became energetic and eloquent.