Vary by category
[计] 依分类变化
🧩 词语组成解析
by
[baɪ]
prep. 在…旁边;表示方式;由于;经过;
adv. 经过;表示保留或保存时用;短暂拜访;
🗣️ 情景例句
Yes?
什么事？
I'm sorry to have kept you waiting.
很抱歉，让你久等了。[分词作状语]
has spent his lifetime studying active volcanoes and deep caves in all parts of the world.
花了毕生的精力来研究世界各地的活火山和探洞。