🧩 词语组成解析
upon
[ə'pɑn]
prep. 在…上面;当…时候;
🗣️ 情景例句
Soon.
很快。
She knew that a vocation this year was out of the question.
她知道今年不可能有假期。
I have a letter of introduction here.
我这儿有一封介绍信。