他们正在唱歌和跳舞 They are singing and dancing
他们正在唱歌
They are singing.
以上为机器翻译结果，长、整句建议使用 人工翻译 。
当你工作的时候，他们正在唱歌吗？
Were they singing while you were working?
youdao
我们到的时候他们正在唱歌。
They were singing when we arrived.
They were singing while we arrived.
应用推荐
模块上移
模块下移
不移动