1.be shocked后面的介词究竟用哪个

后面的介词用at/by，中文意思是，对……感到震惊

You will be shocked at how much you can tighten your prose without losing anything.你会惊讶于没有任何损失的情况下文章能瘦身那么多。

We cannot but be shocked by the extent of its destructive results.我们不能不被其做到的破坏程度吓倒。