（）是社会科学研究和社会工作基本方法之一。
A、社会调查
B、统计分析
C、社区工作
参考答案：A
Mum, I arrived at the train station twenty minutes ago, but Betty up yet.[ ]
A. hadn't turned
B. won't turn
C. hasn't turned
D. didn't turn
钢化玻璃表面不得有损伤，（）以下的钢化玻璃应进行引爆处理。
A.6mm
B.8mm
C.10mm
D.12mm
