题目

Black FridayThe day after Thanksgiving is the start of the holiday shopping season. Thanksgiving is always on a Thursday, so the day after is a Friday. This day has come to be known as Black Friday. It has been the busiest shopping day of the year since 2005.Most stores offer great deals on Black Friday. They open their doors in the small hours of the morning. They try to attract shoppers with big discounts. Some items like TVs are much cheaper than usual. Stores may even lose money on these items. They hope that shoppers will buy gifts for other people while they are in the store.Black Friday如图甲所示，在“用双缝干涉测光的波长”的实验中，（1）光具座上放置的光学元件依次为：①光源、②　　　　、③　　　　、④　　　　、⑤遮光筒、⑥光屏.（2）如果将灯泡换成激光光源，该实验照样可以完成，并测出光波波长.这时可以去掉的部件是　　　　(填数字代号).（3）转动测量头的手轮，使分划板中心刻线对准第1条亮纹，手轮的示数如图乙所示；继续转动手轮，使分划板中心刻线对准第10条亮纹，手轮的示数如图丙所示，则条纹的间距是　mm.（保留3位有效数字）　　　（4）如果已经测得双缝的间距是0.30 mm、双缝和光屏之间的距离是1 m，则待测光的波长是　　　　m.(结果保留3位有效数字)