案：B．

结合上文Itshouldn'ttakelongtoclearupafterthepartyifweallvolunteertohelp．晚会后如果我们都主动帮忙的话，那就不会花很长时间来打扫干净．Many hands make light work人多好办事；Something is better than nothing意为：有比没有好；聊胜于无；Itneverrainsbutpours不鸣则已一鸣惊人，Theearlybirdcatchestheworm早起的鸟儿有虫吃，故选B．