—Now computers      ____   everywhere.

—I agree with you. I think they are the most useful inventions.[ ]

A. are using    

B. use  

C. are used    

D. will use

肺部听诊闻及散在干、湿啰音，多在背部和肺底部，其多少及部位不定，此特征见于

A．慢性支气管炎
B．支气管扩张
C．支气管哮喘
D．心源性哮喘
E．肺炎球菌肺炎