Competitors are allowed to take a five-minute break every hour to eat，drink or do is necessary
A. which
B. that
C. where
D. what
网友回答
A. which
B. that
C. where
(答案→)D. what
解析：考查宾语从句：句意：参赛者被允许每小时休息5分钟去吃东西，喝水和做必要的事情。Do后面缺少宾语从句，宾语从句中缺少主语，用what连接宾语从句。选D。