動詞 perk up:

1. gain or regain energy
   同義詞：perk, percolate, pick up, gain vigor
2. cause to be alert and energetic
   同義詞：stimulate, arouse, brace, energize, energise

1. He looked depressed but perked up when his friends arrived.
   他看上去無精打彩的，但朋友一來就精神起來了。
2. The horse perked up its head when I shouted.
   我吆喝時那馬揚起了頭。