These kids are quick at learning. We had better have them in a new way.
A. having been trained
B. training
C. being trained
D. trained
网友回答
A. having been trained
B. training
C. being trained
(答案→)D. trained
解析：考察非谓语动词。句意：这些孩子们学的很快。我们最好用一种新的方法训练他们。使役动词后接过去分词表示把某事做了。故选D。