I knocked on the door but nobody answered.

我敲了门，但无人应答。

I knocked on the door but there was no response.

我敲了门，可是没有回应。

The attacker knocked on their door and made a lunge for Wendy when she answered.

袭击者敲了他们的门，并在温迪开门时，向她猛冲过去。

When we knocked on her door, she seemed tense but allowed us in any way.

当我们去敲她的门时，她似乎很紧张，但还是让我们进去了。

She went directly to Simon's apartment and knocked on the door.

她径直走到西蒙的住处，敲了敲门。