浇筑芯柱的混凝土,宜选用专用小砌块浇筑混凝土,当采用普通混凝土时,其坍落度不应小于( )mm。
A.60B.60C.80D.90
参考答案:D
根据首字母及中文提示写出单词的适当形式。
1. Our teacher lives n______.
2. We think the Chinese food is w______.We all love it.
3. It's a fine and s______ day, isn't it?
4. There's nothing ______ (剩下) in the fridge.
5. My mother______ (订购) milk for me as breakfast.
6. We are going to the park i______ of staying at home.
7. There is much air ______ (污染) in my hometown.
8. I like all the ______ (当地的) food in the restaurants.
平静呼吸时肺通气的阻力主要是()
A.胸廓的弹性回缩力
B.气体进出气道时产生的摩擦阻力
C.胸廓的惯性阻力
D.肺的弹性回缩力
E.肺组织移位的惯性阻力