【单选题】集中式船舶空调装置常允许采用一部分回风是因为____。
【简答题】My little daughter's wish is ________ (take) to Disneyland this summer holiday.
【简答题】N 型硅,电子迁移率是空穴迁移率的二倍,少子寿命为 1 微秒,温度 300K 时热平衡电子浓度为 10 15 cm -3 。现用光照射该样品,光被半导体均匀吸收,电子和空穴对的产生率是 10 20 cm -3 ·s -1 ,试计算 : 1. 光照产生的非平衡载流子浓度 2. 电子和空穴的准费米能级 3. 光照前后电导率的变化率 4. 光照突然停止 1 微秒后,半导体中非平衡载流子浓度
【单选题】—Are you here on business? —No, .This is my holiday.
【简答题】理论上来讲,有哪些方式可以减小两表面间的辐射传热量?
【简答题】I heard you had left our Disneyland admission coupons at home. Yes. But we were lucky not to leave our visas. __________, we would have had to return home.A. Otherwise B. And C. However D. So
【单选题】— Hey, I heard you had left the company. Why did you do that? — _____________ I resigned was the company never kept its promises.