session做先行词引导的定语从句用什么关系词?session是否可以看做抽象名词后面跟where?例句.

不一定的.
place当先行词,引导词都不能说一定用where的.
It was also found that during the session where the mother smoked,the length of sleeping times was shortened.
母亲吸烟后观察期间婴儿睡觉时间缩短.
And it is commonly believed that such session which does not use the IAC.
而且,这样的不用IAC的会话通常被相信.
He'd been taking part in a mysterious group therapy session which ended in tragedy.
他参加了一个神秘的医疗组织,最终惨败收场.

不能肯定，看具体语境！