单词：for once
就这一次
for once的用法和样例：
例句
- For once, she lost/dropped her customary reserve and became quite lively.这次，她一反平素的沉默寡言，表现得很活跃。
- It wouldn't hurt (you) to say sorry for once.说一声对不起(於你)没有什麽不好。
- Just for once he arrived on time.只有这次他是按时到了。
- Can't you be serious for once?你就不能严肃点吗?