Vendors were doing a brisk trade in souvenirs.

　　小販們的紀念品生意很興隆。

　　There's nothing like a brisk walk on a cold day!

　　冷天出來(lái)快步走走，簡(jiǎn)直太舒服了。

　　He felt strangely exhilarated by the brisk, blue morning.

　　他由于一個(gè)生氣勃勃、藍色的早晨而感到奇怪地極度興奮。