同意博士老师的解答。
句中的 as it should be 为表语从句。
请看以下从《英语动词句型和使用(第2版)》(对外经济贸易大学出版社)第61页摘录的相关内容:
主语+be+as 或 as if 从句
1. Every thing is just as it should be. 一切都正常。
2. Every thing was as he had left it. 一切东西都像他原来放的那样原封未动。
3. It was almost as if every body had come to know it. 好像是人人都已经知道了这事似的。
4. It was as if everything were all right. 好像是一切都很好似的。
5. It’s not as though he were poor. 他不像是贫穷的样子。
【注解】
1. 在本句型中,由连词as 或连词短语 as if 或 as though 所引导的从句作主语补足语。这种主语补足语从句是形容词性的,不可与主语调换位置。
2. 例句4—5:as if 和 as though 可以互相替换。