第三人称单数：throws in 现在分词：throwing in 过去式：threw in 过去分词：thrown in
1.投入,扔进
2.发边界球
3.注入;插入;使(齿轮等)咬合,接合;【电学】接通;添加
1.to include something extra with something that you are selling, without asking for more money
2.to add a remark, question, etc. in a conversation
throwing inthrowing inthrowing in