Question

Samuel Smiles, a British writer, said that practical wisdom is only _______ the school of experience.

1. A.
   to be learned in
2. B.
   learning
3. C.
   to learn in
4. D.
   to be learning

Answer 1

A
宾语从句表示“实用的知识只有通过亲身体验才能学到”。此处是“be+不定式（learn与practical wisdom为动宾关系，应用被动式）”结构。