【单选题】某桥式整流电路,变压器二次侧电压为10V,则输出电压为()
【单选题】下列对文章的理解与分析,不正确的一项是
A.
作者用“青出于蓝”“冰寒于水”两种生活现象说明学习可以使人提高,实现超越。
B.
第一段用“輮以为轮"来推导出通过学习和“参省乎已”才能达到理想境界的结论.
C.
第二段用“跂而望"不如“登高之博见"这种生活体验阐明“善假于物”的重要性。
D.
第三段通过正反对比论述了只有积累、持之以恒和专心致志地学习,才能有所成就。
【单选题】Na 2 O 2 在碱性条件下可体现出很强的经()
【单选题】完成章节部分Period 1-2 Unit 3 Weather 部分的听力选择题。 Part B Question 2 What do you know about Alan?
A.
He thinks the department has misjudged the weather situation for the day.
B.
He dismisses the idea of having an annual picnic as silly.
C.
He dislikes pre-arranged activities and would rather go somewhere on his own.
D.
He prefers a short little sleep after drinking.
【单选题】完成章节部分Period 1-2 Unit 3 Weather 部分的听力选择题。 Part B Question 1 Waht are Alan and Michelle mainly doing?
A.
They are planning a picnic for the department.
B.
They are wondering what the weather will be like at the annual picnic.
C.
They are discussing how to escape from the sun.
D.
They are having cold drinks and talking about the weather.
【简答题】若将上题中两薄壁小孔串联在执行元件的回油路上,其他条件不变,试求串联两小孔的进口压力Pi。