[解析]
(1)B.细节理解题.根据文章第一段 being stolen twice被偷了两次,可以得知Darwin的信件被偷了一次以上.故选B.
(2)A.推理判断题.根据第三段第二句"Their art crime team recovered the letter but were unable to press charges because the time of limitations had ended."他们的艺术品犯罪小组找到了这封信,但由于时效已过,无法提出指控.可知,由于超过了时间限制,因此不能够起诉犯罪团伙了.故选A.
(3)D.细节理解题.根据文章倒数第二段One of our goals is to get intents of high research value or interest to the public online".我们的目标之一是在网上获得具有高研究价值或兴趣的意向".可知,这些照片可以在网上看见.故选D.
(4)B.推理判断题.根据文章最后一段 "and we keep our high value objects in a safe that I can't even reach"."我们把价值很高的物品放在我甚至够不着的保险箱里".可知档案馆采取了安全措施.故选B.