There are usually long lines waiting for assistance and for use of the computer card catalogue.

说等待帮助和使用电子卡片目录总是要排长队。

You should have no trouble getting help and using the card catalogue during the following periods: 11: 30 am to 2: 30 pm; 5: 30 pm to 7: 30 pm.

30—14: 30和17: 30-19: 30的时段里，您能方便地得到帮助和使用电子卡片目录。