George is going to talk about the geography of his country, but I'd rather he _____ more on its culture. [ ]

A. focus

B. focused

C. would focus

D. had focused

下面有关支气管哮喘的描述，不正确的是解（）

A.诱发哮喘的过敏源可以是花粉、尘埃、动物毛屑等

B.严重病例常合并慢性支气管炎

C.镜下可见支气管壁平滑肌增生肥大

D.发作时引起呼气性呼吸困难常伴有哮鸣音

E.哮喘发作时症状不会自行缓解，均需治疗才能缓