【俚语】

pitch in —一起帮忙,作出贡献

最常见得意思是一起帮忙，做出贡献(to join in and help someone with something).
注意：pitch in还有其他的意思：
1.分担共同担负的费用；捐献(某物)；(以某物)支援：
2.投入；把…扔进去：
3.大吃特吃，开始大吃

【例句】

1.When they took up a collection for the annual dinner, he promised to pitch in.
当他们为一年一度的聚餐筹款时，他答应捐款。
2.Please pitch your waste paper in here.
请把废纸扔在此地。

3.As soon as the food was put on the table, all the children pitched in without waiting to be invited.
食物一端上桌子，孩子们用不着请便大吃起来。