Piston knock
[机] 活塞敲击
🧩 词语组成解析
piston
['pɪstən]
n. <机>活塞;
knock
[nɑk]
n. 短促的敲打（声）;爆震声;敲击声;敲门（或窗等）声;
vi. 猛烈敲击;与某物相撞;撞到了桌子;
vt. （心）怦怦跳;把…撞击成（某种状态）;批评;
🗣️ 情景例句
The baby-sitter called.
临时保姆打电话来了。
Is this your book?
这是你的书吗？
Its wool, which had been dyed black, had been washed clean by the rain!
原来羊毛上染的黑色被雨水冲掉了！