動詞 send in:

1. mail in; cause to be delivered
2. give one's name or calling card to a servant when making a formal visit

1. I will like to know what we shall have to do if we agree to send in our bid.
   我想知道，如果我們同意投標應該做哪些事情。
2. After the scandal, he have to send in his papers.
   出了丑聞後，他不得不辭職。
3. I've decided to send in an agent to gather intelligence, but if he gets caught it will stir up a hornet's nest on the diplomatic front.
   我已決定派一名特工人員去收集情報，但是如果他被抓住的話，那就會給外交戰(zhàn)線帶來麻煩。
4. The general decided to play his ace and send in the tanks.
   將軍決定使出絕招，派坦克參加戰(zhàn)斗。