【简答题】小明探究凸透镜成像规律的实验装置如图所示。焦距为10cm的凸透镜固定在光具座上50cm刻度线处,光屏和点燃的蜡烛位于凸透镜两侧。小明将蜡烛移至20cm刻度线处,移动光屏直到光屏上出现烛焰清晰的像,则该像是倒立、 的实像。保持此时蜡烛、凸透镜位置不变,将凸透镜换为焦距为20cm的凸透镜,移动光屏直到光屏上出现烛焰清晰的像,则该像是倒立、 的实像。
【简答题】小英探究凸透镜成像规律的实验装置如图所示,其中焦距为12cm的凸透镜固定在光具座上,位于50cm刻度线处,光屏和点燃的蜡烛位于凸透镜两侧。小英将蜡烛移至20cm刻度线处,移动光屏,直到光屏上出现了烛焰清晰的像,则该像是倒立、_______的、(选填“放大”“缩小”或“等大”)________像(选填“实”或“虚”)。小英将蜡烛移至40cm刻度线处时,她通过凸透镜看到了烛焰的像,则该像是______...
【单选题】I was writing a report last night; ________ I would not have stayed up late.
【简答题】Dr. Ford said that the role as a physician was______.
【简答题】beautician electrician magician musician politician physician technician comedian
【简答题】beautician electrician magician musician politician physician technician comedian
【单选题】内存一般按_分成许多存储单元,每个存储单元都有一个编号,称为内存地址。
【单选题】You cannot see the doctor______you have made an appointment with him.