Ridley investigates a jewelry heist that turns into a murder case, working with an undercover source whose cover soon risks being compromised. Ridley checks out the manager of the jewelry company, thinking it could've been an inside job.。抗生素是抑制细菌生长或杀死细菌的药物类别。抗生素拯救了亿万人的生命,但滥用抗生素也将造成危险后果。Angela Rippon讲述抗生素的历史和应用,以及科学家寻找替代药物的努力。。