承諾的英文：
effort
acceptance
undertaking
promise to do sth.
promise to undertake
undertake to do sth.
acceptance of offer

effort是什么意思：
n. 努力，尝试；成就；杰作

It was a vain effort.
这种努力是徒劳无益的。

That effort will be bootless.
那种努力将是无益的。

You must not relax your efforts.
你不可以松懈你的努力。

acceptance是什么意思：
n. 接受；赞同；承认；相信；承兑

ineligible acceptance
不合格的银行承兑汇票

accept [take up] a challenge
接受挑战,应战

accommodate by accepting time
通融接受远期信用证

undertaking是什么意思：
n. 事业，企业；保证
v. undertake的现在分词

to bear; to shoulder; to undertake; to assume
担负

A chivalrous or adventurous undertaking.
大胆的或冒险的经历

Their installation proved a laborious undertaking.
要来安顿这些人，确实是一件麻烦的事情。