at a time造句

Niccolini was thundering up the stairs, taking them two at a time.
尼科利尼一步两个台阶地噔噔跑上楼。

Add the cream a few drops at a time.
每次加几滴奶油。

For months at a time, air raids were a nightly occurrence.
一度有几个月，每天晚上都会发生空袭。