at 可以表示“在做,在……過程中”,后跟不可數(shù)名詞或單數(shù)可數(shù)名詞,構成固定詞組,常作表語,前面用be動詞。
Li Ming is at work. 李明在工作/在辦公。
They are at rest. 他們在休息。
The children are at school. 孩子們在上學。
They are at their meal. 他們在吃飯。(也可以說at meal )
Who is at the violin? 誰在拉小提琴?(樂器名詞前要用the )
The two countries are at war. 這兩個國家正在交戰(zhàn)。