尽管推迟原因不详，但是新日期定在了一场重要的纪念日之后。
The reason for the delay was not immediately clear, but the new date falls immediately after an important anniversary.
一项新的调查研究发现，双胞胎孩子比起普通小孩，在童年时患癌症的可能性要小，但原因不详。
For reasons that are not clear, twins are less likely than other kids to develop cancer in childhood, the results of a new study suggest.
结果286例儿童热性惊厥有明确病因，分别为呼吸道感染212例，消化道感染74例，原因不详150例。
Results 286 cases had clear cause, the disease cause of 212 cases were respiratory tract infection, 74 cases were infection of digestive canal and 150 cases was unclear.
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