请教个although接分词的问题

Chuckle

我看OG 13 SC第74题的解释中说“Although is a conjunction and should be followed by a finite clause with a subject, not by a participle”。
这句话的意思是说although根本不能接分词吗？
可是我看平时although接分词的句子很多呀！
比如：Although working very hard, he failed to pass the exam.

到底although能不能接分词呢？ OG的这句话又该怎么理解呢？

bejamin1111

连词，连接两个完整的句子，你的例子有问题

kiwifoodtown

尽管连词后面必须接从句，但如果是分词短语作状语的，是可以与连词连用的，这相当于简化后的状语从句保留了连词。这里有两个例子就很说明问题。
Although still running in a number of cities, the electric trolley has for the most part fallen into disuse.
Although usually living on or under rocks or coral reefs, marine snails have been observed in a great variety of habitats.

GMAT应该不会不明白分词作状语的这些用法，而且很多题目也是这样的结构。但是那个解释又很绝对，LZ能不能吧题目贴出来，一起讨论讨论。

cinderellahjy

although后面不是只能接完整句子吗？除非是主系表结构可省？