Question

请教大家一个关于英语的问题，谢谢！！

To their surprise, the precious parcel was full of stones and sand!
这个句子中，To their surprise 这个介词短语起什么作用？做什么成分？

Answer 1

To their suprise = For your information.
precious parcel = greatest land

so the full sentence mean :

for your information, the greatest land was full of stone and sand.

Answer 2

令他们惊讶的是，