I can't pass level 688 what can I do????

Hi @Rejaul, welcome to our community.  I would like to take a moment to offer you a message for all newbies to learn more about our community which you can find here.  We always run contests so be sure to enter them for a chance to win gold bars.

Here is a tip from someone who is very good at writing tips.  You might want to hold on to her link for future levels.