不知所以然的 meaning in English

bewildered

When the bewilered troops were in line, the colonel who had spoken first advised them .
不知所以然的兵士们站队完毕，第一个喊话的上校训话了。
A curious phenomenon has long puzzled developmental psychologists : why do babies seem incredibly smart in some experiments yet utterly clueless when tested with other tasks designed to measure the same knowledge
长久以来，发展心理学家一直对一个奇妙的现象感到困惑：为何婴儿在某些实验中看起来聪明得令人难以置信，但在其他设计来测量相同知识的测验中，却又一副完全不知所以然的样子？