已知:xa=4,xb=3,则xa-2b=( )。
目前认为,可以肯定改善COPD、慢性肺心病患者长期预后的治疗措施是()
A.长期吸入抗胆碱能药
B.长期吸入糖皮质激素
C.长期小剂量口服氨茶碱
D.戒烟和长期氧疗
E.肺减容手术
If you don't promise to help build more houses, ordinary people()
A.will not be nefit
B.would not be nefit
C.should not be nefit
D.could not be nefit