Question

When I entered the classroom, I found all the students____ ready for class.

A. had seated B. seated C. had sat D. seating
答案选B，请问A 为什么不对？

Answer 1

你要先分析主句的结构，I 是主语，found是谓语，all the students是宾语， 而后面的ready for class 是宾语补足语， 所以这个句子已经有完整的主谓宾 很明显这个答案是只能做students的后置定语，这也是为什么不能选择A的原因，因为had seated 不能做定语，只能做谓语。
比如，I find this movie interesting。这就是典型的主语加谓语加宾语再加宾补。
你会选错是因为你以为find后面加的是宾语从句，但是如果加了宾语从句，句子会有一点点变化。
I found (that) all the students seated were ready for class.
而且，seat是个及物动词，要加宾语，不然就用 be seated.正确答案应该是 had been seated。
I found （that) all students had been seated ready for class.

追问

请问C 为什么不能选啊?