兩個詞在意思上有差別的。
reveal v. 揭示，揭露
〔辨析〕
指揭露此前不為人知或隱秘的事，常可與 disclose 換用。
〔例證〕
She will never reveal/disclose her friends' secrets.
她絕不會泄露朋友的秘密。
Details of the murder were revealed/disclosed by a local newspaper.
壹家地方報紙披露了謀殺的細節。
show v. 顯現，顯出
〔辨析〕
語氣較強，強調明顯地表現出來。
〔例證〕
Her worry showed in her eyes.
她的眼神顯露出憂愁。
Spain's economy began to show signs of recovery.
西班牙的經濟開始顯露出復蘇的跡象。