51. of去掉 realize是及物动词,去掉of。
52. had→ have in the past few years是现在完成时的标志性短语。
53. and→ but not only ..but also 固定短语。
54. took→ taken 根据句意可知是被动语态。
55. become →became 根据took可知用一般过去时。
56. in 后加the 特指前句中的photo。
57. they→ that/which 定语从句用that或者which指代photos。
58. difference →different 修饰名词用形容词。
59. late →latest 意思是最新的,用latest。
60. your→ our 根据句意可知指我们的,用our。