penetrating; trenchant;incisive; pierce beneath the show ? 寫作時只有字斟句酌，文章才能～，擊中要害。Only by weighing every word in writing can one write penetrating articles and hit the nail on the head.
鞭辟入里biān bì rù lǐ
鞭：鞭策；辟：透徹。形容說理透徹，切中要害。trenchant,incisive, penetrating, demonish a writing by penetrating criticism