and short of breath Andy and Ruby were the first to reach the top of Mount Tai.A. To be t

问题补充：

and short of breath，Andy and Ruby were the first to reach the top of Mount Tai.

A. To be tired

B. Tired

C. Tiring

D. Being tired

答案：

A. To be tired

(答案→)B. Tired

C. Tiring

D. Being tired

解析：形容词短语修饰主语。Tired疲惫；句意：感觉很疲惫且上气不接下气，Andy和Ruby是第一个登上泰山顶的人。故B正确。