提示词语:visit, touch, impress, meaningful, amazing, memory
提示冋题:1) When and where did it happen?
2)What did you experience?
3)Why was it beautiful?
The movie was Dunkirk, a
如图所示是探究“凸透镜成像规律”的实验装置:
已知△ABC的边BC=4cm,⊙O是其外接圆,且半径也为4cm,则∠A的度数是____.
电磁波家族有无线电波、红外线、可见光、紫外线等,在真空中传播时,它们的____相同(选填“频率”、“波长”或“波速”);红、____、蓝三种色光称为光的三原色.