乙炔瓶工作时要求（）放置。A.水平 B.垂直 C.倾斜 D.随意 发布时间：2019-08-20 13:33 │ 来源：www.tikuol.com 题型：单项选择题 问题： 乙炔瓶工作时要求（）放置。A.水平B.垂直C.倾斜D.随意
题型：单项选择题 完形填空。 Lily is a little girl. She is not ① . She ② how to read or write. But her sister Jill is ③ . She is ten years old. She knows how to read and write. One day, Jill ④ her little sister in the room. She looks ⑤ the table. There ⑥ a pencil in ⑦ hand. She is writing. "What are you writing, Lily?" she asks. "I'm writing ⑧ my friend Rose. " " ⑨ how can you? You don't know how to write," says her sister. "Well," says Lily, "It doesn't matter. Rose doesn't know how to ⑩ , either. "（ ）①A. at school （ ）②A. doesn't know（ ）③A. school girl （ ）④A. write （ ）⑤A. or （ ）⑥A. how （ ）⑦A. my （ ）⑧A. from （ ）⑨A. Or （ ）⑩A. dance B. work B. know B. school girls B. reading B. under B. is B. their B. to B. So B. sing C. study C. don't know C. boy student C. seeing C. at C. are C. his C. for C. But C. write D. a student D. doesn't knows D. student girl D. sees D. in D. have D. her D. with D. And D. read 查看答案
题型：单项选择题 在数据库应用系统的需求分析阶段，需要进行性能分析。下列关于数据库应用系统性能指标的说法，错误的是______。A．数据访问响应时间是指用户向数据库提交数据操作请求到操作结果返回给用户的时间B．系统吞吐量是指在单位时间内系统能存储的数据量C．并发用户数是指在保证单个用户查询响应时间的前提下，系统最多允许同时访问数据库的用户数量D．系统性能指标是系统软硬件设计和选型的重要依据 查看答案