1.Because of this, researchers are trying to identify unusual species that cause disease in order to improve treatment strategies.
正因为如此，研究者们试图识别出那些导致疾病的不常见的细菌种类，从而改进治疗策略。
2.More unusual species of bird are merlin, peregrine falcon, corncrake and chough.
不大常见的鸟类品种有灰背隼、游隼、秧鸡和红嘴山鸦。