问题补充:
— Food problem is becoming a big one in China!
—I think the food before going to shops or supermarkets.
A. is checked
B. is checking
C. should be checked
D. should check
答案:
A. is checked
B. is checking
(答案→)C. should be checked
D. should check
解析:句意:食品问题正在成为中国的一个大问题!我觉得在去商店或超市之前应该检查一下食物。food是check这一动作的承受者,该用被动语态, 结合句意,此处应用带情态动词的被动语态,所以选C。