. The school has recently decided that students aren’t permitted to use mobile phones at school, but I find it difficult to _______ this decision..

A．confirm

B．entitle

C．justify

D．testify

下列对胸膜腔内压的叙述，错误的是

A．负压是由肺的弹性回缩力造成的

B．食管内压可间接反映胸膜腔内压力的变化

C．平静呼吸时，吸气末胸膜腔内压低于呼气末

D．气胸时，胸膜腔内负压减小或消失

E．胸膜腔内负压有利于静脉回流