🧩 词语组成解析
percussive
[[pə'kʌsiv]]
a. 敲击的, 有强大冲击力的, 令人震惊的, 叩诊的
instrument
['ɪnstrəmənt]
n. 仪器;手段，工具;乐器;法律文件;
vt. 用仪器装备;为演奏谱曲;向…提交文书;
in内+stru=struct建立+ment表名词→内部结构→仪器；工具
🗣️ 情景例句
Unless in uniform, he doesn't look like a policeman.
除非穿上制服，要不他看起来不像警察。
How much will the hospital bill be?
住院费大概是多少钱？
If they knew how difficult it was to drill through the hard rock, they would lose heart.
如果他们知道了钻透那坚硬的岩石有多么困难，他们会丧失信心的。