第19题: [单项选择]公路桥涵混凝土用水的硫酸盐量按硫酸要离子计不得超过()mg/cm3。 A. 0.20 B. 0.27 C. 0.35 D. 0.40 参考答案:B
第20题: [单项选择]What time is the conversation taking place A. Christmas. B. Rush hour. C. In the morning. D. Spring. 参考答案:A 答案解析:[听力原文] M: I’m exhausted from the shopping. I had to fight through the crowds. W: It’s always t