波纹管补偿器的特点不包括( )。
A. 补偿量大
B. 安装与检修都较方便
C. 价格较贵
D. 内压轴向推力小
装配式桥梁构件在脱底模、移运、吊装就位时,混凝土的强度不应低于设计所要求的吊装强度,一般不得低于设计强度等级值的( )。
A. 65%
B. 70%
C. 75%
D. 80%
Questions 29 and 30 are based on the following news. At the end of the news item, you will be given 10 seconds to answer the questions. Now listen to the news. Michael Schumacher got injured while he was ______.
A. skating in the French Alps
B. skating in the German Alps
C. skiing in the French Alps
D. skiing in the German Alps
与悬浮一密实结构的沥青混合料相比,关于骨架一空隙结构的黏聚力和内摩擦角的说法,正确的是( )。
A. 黏聚力大,内摩擦角大
B. 黏聚力大,内摩擦角小
C. 黏聚力小,内摩擦角大
D. 黏聚力小,内摩擦角小