Step piston
[化] 级差活塞; 阶梯形活塞
🧩 词语组成解析
step
[stɛp]
n. 步，脚步;步骤，手段;步调;级别;
vt.& vi. 举步，行走;踩，踏上;跨入;轻快地走;
vi. 踏，踩;走;
vt. 跳舞;迈步;使成阶梯状;
piston
['pɪstən]
n. <机>活塞;
🗣️ 情景例句
but there's a letter here addressed to you,
这确实有一封信是寄给你的。
To enter outer space
飞出大气层，进入外太空
Libraries made education possible, and education in its turn added to libraries: the growth of knowledge followed a kind of compound interest law, which was greatly enhanced by the invention of printing.
藏书使教育成为可能，而教育反过来又丰富了藏书，因为知识的增长遵循着一种“滚雪球”的规律。印刷术的发明又大大提高了知识增长的速度。