一个句子的疑惑...Buildings begin to look less somber,as if they wer

是虚拟.你需注意,as if后面可以接虚拟也可以不接虚拟.我记得老师讲的是这个东西像但是它不是就用虚拟,比如The dog runs very fast,as if it were a horse.这里狗不是马,它只是速度上想马,所以用虚拟.再如,He looks so sleepy,as if he stayed up very late last night.这里说他是好像熬夜熬得很晚,他可以成就这件事,因此不用虚拟.
本题中：建筑物不能sleep,所以是虚拟