At the start of a cross-subject（语境补充词）/cross-subject/ challenge, Leo's team received a real case rather than a textbook（教科书）/'tekstbuk/ exercise. The opening evidence connected description（描述、说明）/di'skripʃәn/, desert（沙漠、应得的赏罚）/'dezәt. di'sә:t/, deserve（该得到、值得）/di'zә:v/, design（设计）/dɪˈzaɪn/, desire（欲望、要求）/di'zaiә/, desperate（不顾一切的、危急的）/'despәrәt/, despite（尽管）/dɪˈspaɪt/, dessert（餐后甜点）/di'zә:t/, destroy（破坏、毁坏）/di'strɒi/, detail（细节）/ˈdiːteɪl/, detective（侦探）/di'tektiv/, devote（投入于、献身）/di'vәut/, diamond（钻石、菱形）/'daiәmәnd/, and diet（日常饮食、议会）/'daiәt/. The links looked unusual, but each detail came from a witness, label, form, or measurement（尺寸、度量）/'meʒәdmәnt/ in the case file. The team has already reviewed the complete plan.

A second folder added differ（不一致、不同）/'difә/, digest（文摘）/di'dʒest/, dignity（尊严、高贵）/'digniti/, dimension（尺寸、次元）/dai'menʃәn/, dinosaur（恐龙）/'dainәsɒ:/, directory（目录、工商名录）/di'rektәri/, disability（无力、无能）/disә'biliti/, disabled（残废的、有缺陷的）/dis'eibld/, disappear（消失、不见）/.disә'piә/, disappointed（失望的）/.disә'pɒintid/, discipline（训练、纪律）/'disiplin/, disease（疾病）/dɪˈziz/, disk（圆盘、磁盘）/disk/, and dismiss（解雇；不予考虑）/dɪsˈmɪs/. Some entries described people and places; others recorded objects, actions, or changing conditions. The students sorted each clue by time and source instead of forcing an early answer. The final choice was explained to everyone at the meeting.

The hardest set included distant（远的、疏远的）/'distәnt/, distinct（清楚的、显著的）/dis'tiŋkt/, distinguish（区别、辨别）/dis'tiŋgwiʃ/, disturb（打扰）/dɪˈstərb/, dive（潜水、跳水）/daiv/, division（分歧；划分）/dɪˈvɪʒən/, dizzy（使晕眩）/'dizi/, dolphin（海豚）/'dɒlfin/, domain（领域、领土）/dәu'mein/, dominate（支配、占优势）/'dɒmineit/, dormitory（宿舍）/'dɒ:mitәri/, download（下载）/ˌdaʊnˈləʊdɪd/, downtown（市中心的）/'daun'taun/, and dozen（一打）/ˈdəzən/. Leo checked spelling and context while a partner marked facts that could be tested. Mina, who led（lead的过去式和过去分词）/led/ the discussion（讨论）/dɪˈskʌʃn/, asked for clear evidence. Then the supervisor（管理者、监督者）/.sju:pә'vaizә/ said, “Do not hide an awkward clue merely because it weakens（削弱、减弱）/'wi:kәn/ your first idea.”

The last working board brought together drag（拖、拖累）/dræg/, dragon（龙、凶暴的人）/'drægәn/, drama（戏剧、戏剧艺术）/'drɑ:mә/, dramatic（戏剧性的、生动的）/drә'mætik/, drill（钻孔机、钻子）/dril/, drought（干旱、缺乏）/draut/, drug（药物；毒品）/drəg/, due to（由于）/du tɪ/, duration（持续时间、持续）/dju'reiʃәn/, dynasty（朝代、王朝）/'dainæsti/, eager（热心的、渴望的）/'i:gә/, eagle（鹰、鹰状标饰）/'i:gl/, earn（赚得、获得）/ә:n/, and ease（安乐、安逸）/i:z/. The group compared the four boards, removed repeated claims, and wrote（写下）/roʊt/ a short reason beside every decision（决定）/dɪˈsɪʒn/. If the first method fails, we can try another one. That rule helped them correct two mistakes without blaming a teammate（队友）/'ti:mmeit/.

They planned to check in（办理登记手续）/ʧɛk ɪn/, check out（办理退房；结账离开）/ʧɛk aʊt/, and set off（出发）/sɛt ɔf/ at safe times. Nobody would go on board（在交通工具上）/ɔn bɔrd/ without checking the notice in advance（提前）/ɪn ədˈvæns/. In case of（万一；如果发生）/ɪn keɪs əv/ trouble, one adult would be responsible for（对……负责）/bi riˈspɑnsəbəl fər/ contact while the student could apply for（申请）/əˈplaɪ fər/ official help. The completed record told（告诉）/toʊld/ a clearer story than the first draft. It did not pretend that every clue was equally important; it showed how disciplined reading, calm cooperation（合作、协力）/kәu.ɒpә'reiʃәn/, and a checkable（语境补充词）/checkable/ decision could turn a crowded case into useful（有用的）/ˈjuːsfəl/ action.