extra
adj. /ˈekstrə/ A2
额外的；附加的
Added to what is normal, expected, or already available.
仙境例句
The Hatter always kept extra cups, since nobody ever washed one.
帽匠总是多备些杯子，因为从来没人洗。
原著这一句
“With extras?” asked the Mock Turtle a little anxiously.
“那你们学校有加修课吗？”假海龟有些紧张地打听道。
卡罗尔原著 · 第 9 章