检测彩泥的开裂性时，应将彩泥制成（）mm的直径，长度大于等于80mm的试样。
A.10±2
B.15±2
C.20±2
D.18±2
参考答案：A
根据句意或首字母填入所缺单词。
1. Cars arc s______ than bikes. And they are also f______ than bikes and buscs.
2. He can run very f______.
3. Don't worry! This place is very s______.
4. There are too many p______ at the train station every day.
5. When you are in d______, please keep calm.
设NA为阿伏加德罗常数．下列叙述中正确的是（ ）
A．标准状况下，22.4 L CO2和O2混合气体中含有的氧原子数约为NA
B．2 mol SO2和1 molO2 混合在V2O5存在条件下的密闭容器中反应，反应后分子总数大于2 NA
C．常温常压下，0.1 mol铁在0.1 mol Cl2中充分燃烧，转移的电子数为0.3 NA
D．1 L 1 mol/L的K2CO3溶液中离子总数小于3NA
