结构推理 这片土地本应建成一个供大家享用的公园，但现在却立起了几栋公寓楼。(should have done)
【正确答案】4．This area should have been made into a park for everyone to enjoy，but now some apartment buildings stand there．
【答案解析】[翻译指导] should have done为虚拟语气，指“本应该怎么样而实际上却没办到”，带有责备的意思。