什么时态,都可以,看下面例句 1. The man was so genial, so I was drawn to him at once. 这人这么和蔼, 我立刻为他着迷. dict.cn 2. We agreed to leave at once. 我们同意立即离开. dict.cn 3. Since she is seriously ill, we have to send for a doctor at once. 既然她病得厉害, 我们要马上去请医生. dict.cn 4. We determined to go to the railway station at once. 我们决定立刻去火车站.