She found it difficult to make friends because of her natural reserve.
她因天性矜持很难交到朋友。
He thought social inequality was all part of the natural order of things.
他认为社会不平等完全合乎事物的自然规律。
She was the natural choice for the job.
做那份工作，她是当然人选。
The body has natural defence mechanisms to protect it from disease.
人体对疾病具有先天性防御机制。