It is strongly remended that the machine every year.
A. are checked
B. should check
C. checked
D. be checked
网友回答
A. are checked
B. should check
C. checked
(答案→)D. be checked
解析:It + be + remended + that从句结构中,that从句应用“ should + 动词原形”,其中should可省略,故选D。