右心室流出道扫描体位主要用于观察（） A.右心室流出道的狭窄情况 B.左心室流出道的

The reason _____ he didn't go to school yesterday was _____ he was ill. [ ]

A. why; that

B. that; because

C. that; that

D. for which; what

川贝母的功效是（）

A．清热化痰，清心定惊

B．清热化痰，润肺止咳

C．清热化痰，消痈散结

D．疏风散热，降气化痰

E．清热化痰，除烦止呕

雾化药物