scarce adj
make oneself scarce 离开，退避
That bird has become scarce in this country.
Food and water are scarce and expensive in the flooded area.
scarcely adv.
表示“几乎不，仅仅”，与when连用时，意思和“hardly…when”相同都表示“一…就”，置于句首
时，用部分到状结构
He had scarcely escaped when he was recaptured
=Scarcely had he escaped when he was recaptured(重新捕获)
