Progress is disappointingly slow.

进展慢得令人失望。

The room was disappointingly small.

屋子小得令人失望。

The first thing we look for is his sandals, but, disappointingly, he's barefoot.

我们首先寻找的是他的凉鞋，但令人失望的是，他是赤着脚。

Disappointingly, the search engine just gave me some brief introductions rather than the whole content of the book to read.

令人失望的是，搜索引擎只给了大概的介绍而没有给出要读的书的全部内容。

Others plop disappointingly.

有些令人失望地“扑通”的掉下去了。