Question

It seems reasonable to assume that ,other things _____(be) equal,they would~~~为什么那么添

It seems reasonable to assume that ,other things _____(be) equal,they would prefer single to shared rooms.

Answer 1

It seems reasonable to assume that ,other things __being___(be) equal,they would prefer single to shared rooms.
= Other things __being_(be) equal,it seems reasonable to assume that they would prefer single to shared rooms.= If other things are eual,it seems reasonable to assume that they would prefer single to shared rooms.在他条件相同的情况下，与其同住一个房间，他们宁愿单住是有道理可言的。other things being equal"在其他条件相同的情况下"是独立主格结构，作条件状语。

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你回答的也很棒，谢谢

Answer 2

being
意思为：其他条件相同的情况下，他们宁愿单住，也不愿意共用房间，这个假设是有道理的。
other things being equal（其他条件相同的情况下）是一个独立主格结构，即意义上具有“主位关系”的结构，但不是严格意义上的语法上的“主谓”，所以动词只能用非谓语形式（不定式、分词等）或者其他结构（如介词短语等）。
独立主格结构在句中常作状语，相当于一个状语从句。
比如本句中相当于if/when/as long as other things are equal。

本句主干就是：It seems reasonable to assume + that 从句

Answer 3

being

Answer 4

being not