be committed to 他的用法具体有多少，

你直接上Google上搜索“is committed to”或者，“are committed to”,你可以得到非常地道的种种用法。记得包括引号。

http://www.google.com/search?hl=en&lr=lang_en&newwindow=1&rls=GGGL%2CGGGL%3A2006-13%2CGGGL%3Aen&q=%22is+committed+to%22&btnG=Search

be committed to do 承诺做某事
be committed to doing 致力于做某事