直流母线至逆变器之间的二极管的作用？
参考答案：
保证只能由直流母线向逆变器供电而不能有别的供电方式。
Our village is changing greatly. Many new houses ______ next year. [ ]
A. are build
B. is being built
C. will build
D. will be built
失血性休克是出血占全身血容量的（）
A.10%
B.15%
C.20%
D.30%
E.40%
