Light upon
（偶然）發現
?? 詞語組成解析
light
[la?t]
n. 光;發光體;電燈;點火器;
adj. 輕的;明亮的;淺色的;少量的;
v. 點燃;照亮;用光指引;
adv. 輕地，輕裝地;
upon
[?'pɑn]
prep. 在…上面;當…時候;
??? 情景例句
what you were thinking about regarding going back to work.
是否打算回去工作。
When was the last time he wrote you ?
他給你寫最后一次是什么時候？
When I boarded the train, I could not help noticing that a great many local people got on as well.
上車后，我不禁注意到許多當地人也上了車。