The group has adventured as far as the Austrian alps.该队伍的探险之旅远至奥地利的阿尔卑斯山。They were killed by an avalanche in the Swiss Alps.他们在瑞士阿尔卑斯山的一次雪崩中罹难.In the distance rose the majestic Alps.远处耸立着雄伟的阿尔卑斯山....
人们相信压力能确实地使免疫系统功能下降.It's believed that stress can actually depress the immune system.由于移植会使免疫系统变弱, 病人在此情况下不能施行手术.Because transplants weaken the immune system, they cannot be performed on sick patients.病原体始终在进化,使免疫系统...