At that second knock, a window on the third floor opened and the same Snail looked out.
第二次敲门时，三楼的一扇窗户打开了，还是那只蜗牛往外看。
2
The following day, a knock on the window woke Harry.
第二天，哈利被敲窗户的声音吵醒了。
3
He was too surprised to resist and when he recovered his wits enough to make like he was going to knock me down, he caught sight of what was going on outside the window and the breath went out of him.