【题目】Nowadays many parents are trying to either prevent their children from failure, or protect them from the knowledge ______ they have failed.
A．that B．when C．where D．which
在线课程【答案】A
【解析】句意：现如今，许多父母要么尽力防止他们的孩子失败，要么不让他们知道自己已经失败的事实。knowledge后面接的是同位语从句，从句意思完整不缺成分，故选that。