利用所给词语写一段话，介绍“征集全民健身口号”活动的结果，要求语意完整，句子通顺，字数在50-60之间。

来源广  一个月  入选口号  千余条  “我运动，我快乐”

答：                                                                                   

                                                                           。

You know he is not going to let us leave early if we ___ get the work done.

A．can't

B．may not

C．shouldn't

D．mustn't