我国规定泵送混凝土的坍落度宜为()
A、5-7cm
B、8-18cm
C、8-14cm
D、10-18cm
参考答案:B
Sandy could do nothing but ______ to his teacher that he was wrong.
A .admit B. admitted C. admitting D to admit
在垃圾箱房、猪棚、牛棚、鸡舍、饲养场、厕所等场所灭虫用()喷洒法好。