More probable is bird transport,either externally,by accidental attachment of the seeds to feathers,or internally,by the swallowing of fruit and subsequent excretion of the seeds.
更有可能的是鸟类运输：或者是通过外部途径，即由于种籽偶然粘附在羽毛上;或者是通过内部方式，即由于鸟类吞食果子并随后将种籽排泄出来。
难句类型 ：复杂修饰、插入语、倒装
解释：句首有一个倒装，正常语序是bird transport is more probable.后面的句子中由于插入部分的频繁出现使句子显得十分凌乱。
意群训练：More probable is bird transport,either externally,by accidental attachment of the seeds to feathers,or internally,by the swallowing of fruit and subsequent excretion of the seeds.