Simplified outline help, please?

I'm on the Reading and Writing Practice 345 and stumped as to two outlines. The sentence before and after reads: You can be sure only if you have been able to make ______    _______ comparisons  with the way other apartments are being operated. (This is the green Simplified book, not the college edition or the later editions.)

For some reason the  two outlines between "to make" and "comparisons" are eluding me. Does anyone else have an idea of what they say?

Thanks :)