While he was watching TV, someone knocked at the door.

正当他在看电视时，有人敲门。

youdao

While he was watching TV, he heard a knock at the door.

正当他在看电视时，他听到有人敲门。

youdao

While I was watching TV, she knocked at the door.

我正在看电视时，她来敲门。

youdao

While I was watching TV, she knocked at the door.

我正在看电视时，她来敲门。

youdao