It’ s suggested by experts that teenagers at least 30 minutes exercising, five times a week.
A. spend
B. to spend
C. spent
D. have spent
网友回答
(答案→)A. spend
B. to spend
C. spent
D. have spent
解析：suggest后的从句用虚拟语气，should+do,should可省略。指advise, suggest, propose, remend，demand, require, request等后的宾语从句，从句谓语由“should+动词原形”构成，其中的should在美国英语中通常可以省略