If you read a number from a file and expect it to be positive, check that it is before further processing with that number.
如果从文件中读入一个数字并期望其为正数，那么，在使用其进行进一步处理前对其先验证一下。
2
I have file drawers filled with positive, grateful personal comments like these.
我的好几个文件抽屉都塞满了像上面那样正面的、充满感激的个人评论。
3
“But negative trials took an extra two to four years to be published,” he noticed. “Negative results sit in a file drawer, or the trial keeps going in hopes the results turn positive.”