The player's career is hanging by a______ after this latest injury to his knee.
【正确答案】 C
【答案解析】最近的这次膝盖受伤使那位球员的运动生涯变得岌岌可危。注：hang by a thread意为“千钧一发，岌岌可危”，所以选C。其他选项无此搭配。