The party had to be______because the host went down with a bad case of flu.
【正确答案】 B
【答案解析】call in:召集,叫来;call off:取消;call on:号召,拜访;call up:提出,打电话,征召……入伍。go down with意为“染上疾病”。根据句意可知,选B。