1:If I ___(know) how to sing the song,I would join you

问题描述:

1:If I ___(know) how to sing the song,I would join you
2:I___(not have) my lunch,so I'm hungry 3:The teacher gave me some___(help) advice 怎么些啊

3.knew 后面是would 前后时态照应
2.didn't have 过去没有吃 用过去时
3.helpful