flesh and blood
up in the air
as poor as a church mouse
tooth and nail
本题考查副词性习语。tooth and nail：竭尽全力地；副词性习语。flesh and blood：亲骨肉；名词性习语。up in the air：悬而未决的：形容词性习语。as poor as a church mouse：一贫如洗：形容词性习语。
