英文小句翻译成中文

我分不清究竟XXX（this的翻译要看上文说的是什么才能决定，这里暂时用XXX代替）是她与生俱来的（本性），还是因为多年的演员生涯使这种情绪演绎成为其第二习性。
if the sentence is made complete, it should read:

I couldn't tell whether this was something she was born with,or whether this was the projection of emotion which she had learned as an actress had become second nature.

which she had learned as an actress had become second nature.为定语从句，修饰projection of emotion. which 主语，had become second nature为从句谓语。从句中套从句，she had learned as an actress 又是一个定语从句，修饰which。释译：她早先作为演员学会了情绪的强烈表现，这种表演已经成为她的第二习性（习惯成自然了）。

我不确定她这种对情感的表达能力是不是与生俱来，也无法肯定这是不是在她作为一名演员而习得的能力，而这能力也已经成为了她的第二种天赋。

我不能分辨这是她与生俱来的，还是作为一个演员对情感的掩饰已成为第二种天性。

我不敢说这是她出生的,或是投影的情感,她就像一位女演员已经成为第二个本性' '

究竟她是天性如此，还是她学习演技时学的情感表现方式已经成为她的另一种性格，我实在无法判断。

我不知道他这种表达情感的能力是与生俱来的，还是作为演员后天学习的但以成为他的习惯。