There are many ways, here is one.
Set thread number is 5, run type is Repeat.
Create a txt file with 100 lines, each line is a data to specify the name of the website you want to crawl.
For each website, create a function to scan the corresponding data.
Create a resource of the form LinesFromFile (Use each line any number of times).
When reading data, for each line received, use the "IF" command to check.
For example, with 1 line in the txt file I denoted by cnn, so when I receive this data, I will execute the corresponding "Call function" command "cnn".
Same goes for the remaining 99 lines, with the other "Call function" commands.

So, when it's done 100 websites, with the initial resource data settings, it will run from the beginning.