对慢性阻塞性肺疾病诊断最有意义的检查是（）
A.胸部X线检查
B.血气分析
C.心电图和心电向量检查
D.肺功能检查
E.肺动脉压测定
参考答案：D
The company's _______ to providing quality at a reasonable price has been vital to its success. [ ]
A. consideration
B. commitment
C. competition
D. contribution
如果风机安装在室外，要有防雨和（）措施。
