Where is Jenny? [ ]
A. She is at school.
B. She is eating.
C. She is a girl.
答案:A
堆垛机超速机构上用的钢丝绳型号为().
A.∮11
B.∮6
C.∮12
砌体水平灰缝的砂浆饱满度不得小于()。
A.90%
B.80%
C.70%
D.60%