题目

当我们吸气时（ ）A. 肋间肌收缩，膈肌收缩 B. 肋间肌收缩，膈肌舒张C. 肋间肌舒张，膈肌收缩 D. 肋间肌舒张，膈肌舒张 答案：【答案】A【解析】试题分析：呼吸肌的收缩和舒张而造成胸腔有规律的扩大与缩小，叫呼吸运动，包括吸气和呼气两个过程，吸气时：肋间外肌、膈肌收缩→肋骨向上向外移动（膈肌顶部下降）→胸廓扩大、胸腔容积增大→肺扩张→外界大气压力大于肺内气压→外界气体进入肺，呼气时：肋间外肌、膈 Mayor will make an inspection of our school on Monday, ___ you can tell him how hard the situation we are in. A. where        B. which              C. when             D. that