同位语从句还是宾语从句？

表语从句。主句部分是The dilemma is whether he should tell thruth to the patient or not.

he dilemma [a doctor often faces]其中的[]是宾语从句， 词句省去了引导词that

区分同位语从句和宾语从句关键在于引导词是否在从句中充当句子成分，如果充当就是定语从句，否则为同位语从句； 另外同位语从句的引导词一般不能省。

The fact that he has done this many times is known to everyone. 此句that引导的是同位语从句。

The fact that they were all curious about is still unknown. 本句that引导的是宾语从句, that 作句中about的宾语

主语从句
The dilemma is whether he should tell thruth to the patient or not作为主句

dilemma是主语

a doctor often faces 做从句修饰，
同位语：http://baike.baidu.com/view/409810.htm

不是同位语从句，也不是宾语从句，是定语从句和表语从句。
a doctor often faces 是修饰dilemma的定语从句，whether he should tell thruth to the patient or not是表语从句。

定语从句，
1.the dilemma that a doctor often faces =there is dilemma. A doctor often faces this dilemma.
The dilemma （a doctor often faces） i