Definition: Infectious laughter or feelings quickly spread from one person to another. Level: C2
她富有感染力的热情迅速传遍了房间里的每个人。
Her ___infectious enthusiasm quickly spread to everyone in the room.
积极情绪常常具有感染力，让其他人也感到更快乐。
Positive emotions are often ___infectious, making others feel happier too.
那位喜剧演员富有感染力的笑声让全场观众捧腹大笑。
The comedian's ___infectious laughter had the entire audience in stitches.
