多项选择题 防渗墙墙体材料主要分为刚性材料和柔性材料。刚性材料主要有（）等。

多项选择题 根据水利工程建设项目招标投标的有关规定，评标标准宜优先考虑投标报价的是（）招标。

问答题 Some people think it is the best approach for students to learn if school start the day at a early time in the morning.But someone think the school should start the day at late time.Which one do you prefer？Use specific reasons and detailed examples to support your answer.