承重结构用砖,其强度等级不宜低于MU10。
参考答案:对
介词填空
1. Have you learned _____ China?
2. I like the report ____ the animals.
3. The little boy takes his dog ____ the park.
肥厚型梗阻性心肌病取样容积置于主动脉瓣下左室流出道狭窄处,收缩期血流呈()。
A.负向、高速、宽频带、层流
B.负向、高速、低频带、湍流
C.负向、低速、宽频带、湍流
D.正向、高速、宽频带、湍流
E.负向、高速、宽频带、湍流