第16题: [单项选择]People were afraid to leave their house, ______ the police had been ordered to stand by in case, of emergency, they were just as confused and helpless as anybody else. A. and even if B. but since C. however after D. for though 参考答案:D 答案解析:for though是复合从属连词。for引导的句子是表示前面内容的原因或理由,though是该句中的从句。全句大意是:“人们不敢离开家,因为一旦出现紧急情况,虽有警察在旁待命,但他们也与其他人一样慌
第22题: [单项选择]污水管道在检查井处的衔接方式,错误的是( )。 A. 当下游管道管径等于上游管道管径时,应采用管顶平接 B. 管道衔接方式有管顶平接,水面平接和跌水连接 C. 管顶平接是使上游管段终端和下游管段起端的管顶标高相同 D. 水面平接是指上游管段末端和下游管段起点在设计充满度下水面相平 参考答案:A