起重机是如何分类的？
参考答案：
起重机分为臂架类起重机和桥架类起重机。臂架类起重机又可分为固定式、移动式和浮式起重机。
---Have you read any novels written by the famous writer Mo Yan?
--- Yes, of course. I ______ several of his works when I was studying abroad.
A．read
B．had read
C．have read
D．was reading
男，35岁，因胃溃疡穿孔出血入院治疗。现已处于恢复期，但病人依赖性增强，超出了病情需要，自己能做的事也要家属或护士替他做，此病人使用哪一种心理防卫机制 ()。
A．转移
B．压抑
C．升华
D．否认
E．退化
