单词学习：held 动词（过去式/过去分词）
held
/hɛld/
（hold的过去式和过去分词）持有；抓住；举行；容纳；保持；认为
The important documents were held by Mr. Gu until the meeting began.
重要文件由顾老师保管，直到会议开始。
单词卡片
卡片已就绪
