两个正方体甲和乙，边长分别是5cm和10cm，甲重10N，乙重30N。如将甲放在乙的上面正中央，求甲对乙的压强和乙对地的压强.

I want to____ ____ ____Chinese history and culture.

阅读下文，回答相关问题。

                                                                                                               春  兴
                                                                                                       （唐）武元衡
                                                                                   杨柳阴阴细雨晴，残花落尽见流莺。
                                                                                   春风一夜吹乡梦，又逐春风到洛城。