履带式起重机变幅应缓慢平稳，严禁在起重臂未停稳前变换档位。
参考答案：对
_____ his writing, the writer forgot to have his lunch. [ ]
A. Was absorbed in
B. Absorbed in
C. Absorbed into
D. Was absorbed into
下列属于股票最基本的特征的是（）。
A.收益性
B.流动性
C.永久性
D.风险性
