He was to find that it was almost impossible to undertake the task. A. cast offB. cast ou

问题补充：

He was to find that it was almost impossible to undertake the task.

A. cast off

B. cast out

C. cast away

D. cast down

答案：

A. cast off

B. cast out

C. cast away

(答案→)D. cast down

解析：短语辨析。 A. 摆脱；抛弃 B. 驱逐 C. 丢掉 D.使沮丧；推翻。句意：发现几乎不可能承担这项任务让他很沮丧。故选D。