【单选题】根据维护规程,在正常使用及维护条件下,机房专用精密空调有效使用年限为( )。
【单选题】'You ___ not be too careful in the exam. Do and check your papers carefully and you ____ not take your papers out of the examination room after the exam.' the teacher told us before the exam. [ ]
【单选题】She ______the knives and forks at the lunch table.
【单选题】She had worked in the cannery the ______ summer, and her slim, pretty hands were all scarred with the tomato knives.
【单选题】月经后使子宫内膜上皮修复的主要是 (1分)
【单选题】“所列问题没有固定的、规范化的标准答案,即问题对每一被访者都是同一的,但事先不做出任何选择答案的问卷”,以上描述是指大学生社会调查中哪种问卷形式( )。
【单选题】She ______ the knives and forks at the table.