She found it difficult to make friends because of her natural reserve.

　　她因天性矜持很難交到朋友。

　　He thought social inequality was all part of the natural order of things.

　　他認(rèn)為社會(huì)不平等完全合乎事物的自然規(guī)律。

　　She was the natural choice for the job.

　　做那份工作，她是當(dāng)然人選。

　　The body has natural defence mechanisms to protect it from disease.

　　人體對(duì)疾病具有先天性防御機(jī)制。